MELBOURNE, Australia -- Much like opening day, Tuesday at the Australian Open was fairly routine, with the top players moving through. Serena Williams dropped only two games against Tatjana Maria, while Novak Djokovic rolled in straight sets.

Simona Halep avoided becoming the first No. 1 seed to lose two consecutive first-round Slam matches to the same opponent, while Naomi Osaka maintained her strong form.

Will we see any major upsets on Day 3? Here are the storylines to watch:

How to watch

Day session

ESPN3 & ESPN+: Starting at 7 p.m. ET

ESPN2: Starting at 9 p.m. ET

Night session

ESPN2: Starting at 3 a.m. ET

*Full Day 3 schedule here

Key storylines

Nadal to play the villain again (and again?)

Rafael Nadal at the 2019 Australian Open. Chaz Niell/Icon Sportswire

More often than not, Rafael Nadal steps onto Rod Laver Arena feeling the love from the stands, but after facing Aussie qualifier James Duckworth in the first round of the Australian Open, Nadal is again set to play the antagonist role when he faces another Aussie, Matthew Ebden, in the second round.

While Nadal, the No. 2 seed, can expect his share of support from the center court crowd Wednesday evening, it's Ebden who could benefit more from rowdy home support.

Fittingly, should Nadal win, he's more than likely going to play local hope Alex de Minaur in the round of 32.

Is the hype surrounding Tsitsipas warranted?

Stefanos Tsitsipas in action. David Woodley/Action Plus via Getty Images

He's the en vogue up-and-comer on tour right now, but it's fair to say Stefanos Tsitsipas needs to prove his mettle in the Grand Slam arena.

The No. 14 seed faces a tough second-round match against journeyman Viktor Troicki. But this match will likely be dictated by Tsitsipas. Last year, he beat Novak Djokovic, Dominic Thiem, Alexander Zverev and Kevin Anderson at the Rogers Cup before falling to Nadal in the final.

Tsitsipas' best finish at a Slam was a fourth-round showing at Wimbledon last year, while his start to 2019 has been indifferent. At the Sydney Open, Tsitsipas, 20, lost to Andreas Seppi in the quarterfinals.

Two upset specialists set to square off

John Millman and Roger Federer shake hands after Millman defeated Federer at the 2018 US Open. Danielle Parhizkaran-USA TODAY SPORTS

After rising from relative anonymity during last year's US Open by beating Roger Federer, good-old-fashioned "Aussie battler" John Millman will face an opponent who himself knows a thing or two about taking down stars.

We're talking about Roberto Bautista Agut, of course, who Monday ended Andy Murray's run here and possibly his career.

Bautista Agut has won all three of their previous matchups, but with Millman being in career-best form, he won't be a pushover.