Melbourne (CNN) It may not have been an upset in the same league as last year's U.S. Open but what happened at the Australian Open on Saturday perhaps wasn't far off.

Angelique Kerber stunned Serena Williams in a 6-4 3-6 6-4 thriller to open her grand slam account and deprive the American of a 22nd title at a major that would have tied Steffi Graf for the Open Era lead.

Just how rare is it for Williams to lose a grand slam final?

She had won her last eight and was 21-4 overall.

Jamie Murray of Britain (right) and Bruno Soares of Brazil lift the men's doubles trophy after beating Daniel Nestor of Canada and Radek Stepanek of Czech Republic in the final.

Jamie at the double – Jamie Murray of Britain (right) and Bruno Soares of Brazil lift the men's doubles trophy after beating Daniel Nestor of Canada and Radek Stepanek of Czech Republic in the final.

Kerber and Williams pose before the start of the final, the first grand slam final for eventual winner Kerber.

Kerber and Williams pose before the start of the final, the first grand slam final for eventual winner Kerber.

Kerber played the match of her life to bring home a first grand slam title.

Kerber played the match of her life to bring home a first grand slam title.

Williams is wrong footed on the baseline by a return from Germany's Kerber.

Williams is wrong footed on the baseline by a return from Germany's Kerber.

Kerber at full stretch in the thrilling women's singles final against top seed Williams.

Kerber at full stretch in the thrilling women's singles final against top seed Williams.

Williams tries her best to pump herself up as a 22nd grand slam title slips away from her grasp.

Williams tries her best to pump herself up as a 22nd grand slam title slips away from her grasp.

Kerber is sportingly congratulated by Williams after closing out victory in the third set.

Kerber is sportingly congratulated by Williams after closing out victory in the third set.

That winning feeling: Kerber celebrates winning an epic three set final against Williams.

That winning feeling: Kerber celebrates winning an epic three set final against Williams.

Angelique Kerber of Germany kisses the Daphne Akhurst Trophy after winning the Australian Open women's singles title in a stunning upset of Serena Williams in Melbourne.

Angelique Kerber of Germany kisses the Daphne Akhurst Trophy after winning the Australian Open women's singles title in a stunning upset of Serena Williams in Melbourne.

And after Kerber upset Williams in Cincinnati in 2012, the world No. 1 reeled off four consecutive victories against the German without conceding a set.

The result followed Williams' semifinal defeat to Roberta Vinci in New York in September, one of the biggest upsets of all time in tennis, and one can't help but ponder if nerves -- or the weight of expectation -- are now getting to the 34-year-old in the most pivotal matches.

"Every time I walk into this room, everyone expects me to win every single match," she told reporters in the main interview room. "As much as I would like to be a robot, I'm not. I try to.

"I do the best I can."

Kerber: "I had goosebumps. My whole life I've worked hard. To say 'I am a Grand Slam champion' is crazy" #AusOpen pic.twitter.com/j9woE4GXfn — Australian Open (@AustralianOpen) January 30, 2016

Her comment resembled Roger Federer's "I've created a monster" line after the Swiss suffered a rare, in those days, loss in the Australian Open semifinals in 2008 to Novak Djokovic. That "monster" was the pressure of having to keep on winning in the wake of repeatedly crushing his rivals.

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"When you are a big favorite in a grand slam final, you are nervous," Williams' coach, Patrick Mouratoglou, told reporters. "If you are not, you are not normal, so she is."

But he added: "She's been much more nervous in other finals that she won. We just have to congratulate Angelique."

Maybe it was simply meant to be for the left-handed Kerber, who became the first German to win a grand slam since her idol Graf in 1999.

The seventh seed saved a match point in the first round against Misaki Doi, emulating Li Na, who escaped from match point down in the third round in 2014 before her title success.

"My phone is exploding right now," said Kerber, who will rise to second in the rankings. "I don't know how many messages I got. It's amazing."

Congrats, @AngeliqueKerber. You are persistence and determination, personified. Soak up this moment. You've earned it! #GoForIt #AusOpen — Billie Jean King (@BillieJeanKing) January 30, 2016

One was from Graf, who additionally sent a text after Kerber's semifinal win over Johanna Konta.

"I think it's so good for Germany, for German tennis," said Kerber. "After Steffi now someone won a grand slam."

Kerber sunk to her knees when Williams erred on a forehand volley long on match point and soon was in tears to end an evening that was marked by the latter's plethora of unforced errors in the first set prior to turning into an absorbing two-hour affair.

Defense over attack

Ultimately it was the counter-punching of Kerber, a late bloomer in tennis, that stifled the attack of Williams, the defending champion.

"I was not playing very good last year in the big tournaments," said Kerber, bundled out in the first week at every major last year. "This is the first big tournament of the year and I won it, the first grand slam. It sounds crazy but I can say I'm a grand slam champion."

Twice in the gripping third set she produced breathtaking passes, striking a forehand down the line and another forehand crosscourt as rallies morphed into mini-marathons.

Given Williams' history, when she rallied from 5-2 down in the third to get to 4-5 and serving, how many picked Kerber to prevail? Yet she did, Williams giving Kerber a match point by missing a forehand into the net and then sending the comfortable looking volley long.

Kerber's sensational retrieving may have been a factor in the miscue but Williams had an abundance of space to place the volley and return to deuce.

Congrats to my countrywomen @AngeliqueKerber !!! Enjoy this moment for the rest of your life...@AustralianOpen #Melbourne — Boris Becker (@TheBorisBecker) January 30, 2016

Overall Williams committed 46 unforced errors.

"I was missing a lot off the ground, coming to the net," said Williams. "She kept hitting some great shots actually every time I came in."

Twenty-three alone came in the first, when the rallies weren't as long as in the third. Williams was misfiring early in points.

Kerber, meanwhile, did her thing on defense and mixed in attack when given the chance, a new-found strategy initiated in the off-season. She tallied 25 winners and made a miniscule 13 unforced errors.

"I think Angie deserved it today because she was fighting for every point," Kerber's coach, Torben Beltz, said as he sipped a glass of red wine. "Going forward and when she had a chance to be aggressive, playing aggressive and going for her big shots."

Beltz was almost in tears himself when he saw Kerber's name inscribed on the trophy.

"I'm feeling like great, emotional," he said. "Unbelievable match. Very emotional for me for sure."

What a final girls @serenawilliams & @AngeliqueKerber Great sportsmanship! Well done to both. Congrats to Angelique for her 1st GS #AusOpen — Novak Djokovic (@DjokerNole) January 30, 2016

An early Kerber break to start the final, then, on a pleasant evening in Melbourne foreshadowed what was to come.

She led 3-1 and 30-0 on the Williams serve.

A Williams charge, though, the kind she engineered last year when battling her way to the title at the French Open, seemed on the cards. From 15-30, a hefty serve prompted a "come on" and there was another "come on" followed by a fist pump when a forehand winner followed.

Williams broke for 3-3 and order appeared to be restored.

But the uncertainty in Williams' game ensued. She was not only off the mark, but erring by a yard long or yard wide. When another forehand went astray to fall behind 4-3, all she could do was offer an ironic smile to her box.

Unforced errors aren't always an indication of how a player is performing, but the first-set numbers in this case were reflective of Williams' lethargy.

Best final ever @AustralianOpen! @AngeliqueKerber is my favourite tennis player from now on 😀 omgggg — Daria Gavrilova (@Daria_gav) January 30, 2016

Kerber's unexpected advantage masked the fact she wasn't serving well. Her first-serve percentage dipped and it was only down to Williams' charity that the 28-year-old was winning points on her inviting second serve.

Winning a set off Williams in a grand slam final is one thing -- it was the first set she lost this fortnight -- but finishing the job is another matter entirely.

Kerber subsequently waned. The aforementioned serve produced two double faults in the fourth game and the Bremen native paid the price to trail 3-1.

Williams was starting to tidy up her game and the second-set statistics proved it: 16 winners and a paltry five unforced errors.

No comeback this time

The expected waltz for Williams didn't materialize in the third. Kerber produced the shot of the match when she lashed the forehand passing shot down the line from well behind the baseline.

She raised her arm in jubilation and her joy escalated when leading 2-0.

A hold for Kerber would have swung the odds in her favor but that didn't happen. Instead Williams broke for 1-2.

The to and fro ensued. Kerber brought the fans out of their seats again with a a cross-court forehand pass, exemplifying her tenacity.

"I think I kept picking the wrong shots coming into," the net, said Williams, who won less than half of her 32 points at the net.

Even when she lost a protracted rally at 3-2 -- Kerber ran 70 meters -- she was sending a message to Williams that she wasn't about to surrender.

Three break points for Kerber came and went in the enthralling sixth game, the third one erased with a backhand into the corner. But on game point, Kerber kept the game going with a deft drop shot, her first of the match.

The pattern continued. Another Kerber drop shot stopped Williams from drawing level. A double fault soon followed and on her fifth opportunity, Williams struck a forehand long to cap the mesmerizing 10-minute tussle.

Kerber held to love for 5-2 and was on the brink of victory at 30-all in the next game. Williams, however, hung on.

Presented with a chance to serve it out, Kerber authored a shaky error on the first point. But Williams stepped up her level, hitting two good returns, including one on a second break point to pull to 4-5.

Ultimately there would be no miraculous comeback as the serve that has gotten Williams out of trouble on so many occasions disappeared.

Williams' final serve numbers were sobering, seven aces and six double faults

"The serve was not there tonight and especially in the big games," said Mouratoglou.

The underdog triumphing could give Andy Murray hope in the men's final. He will play Djokovic, who now seeks a sixth Australian Open crown. The world No. 1 has already toppled Murray in three Australian Open finals and is coming off a resounding semifinal win over Federer.

Doubles omen?

Second seed Murray might also take heart from the performance of his older brother Jamie, who paired with Brazil's Bruno Soares to win the men's doubles title later Saturday.

The new partnership beat veterans Daniel Nestor of Canada and Radek Stepanek of the Czech Republic, another new pairing, 2-6 6-3 7-5 in a match that finished past midnight local time.

Andy, who could not watch the match from the stands through nerves, turned up at the trophy presentation.

But Saturday belonged to Kerber.

"The Australian public and everyone around the world fell in love with you tonight," said tournament director Craig Tiley after leading a toast to Kerber.