Kiwi tennis player Michael Venus taught American doubles partner Ryan Harrison to drive, was a groomsman at his wedding and has now claimed a Grand Slam title with him.

Venus became New Zealand's first Grand Slam champion since 1979 on Sunday morning [NZ time] as he and Harrison toppled Mexican Santiago Gonzalez and American Donald Young 7-6(5) 6-7(4) 6-3 in the French Open men's doubles final.

"You always dream of winning a Grand Slam every time you play," Harrison said. "As a kid you idolise people you see winning Grand Slams, you picture yourselfs in those moments and it kind of hasn't sunk in yet. It feels surreal."

CLIVE BRUNSKILL/GETTY IMAGES Michael Venus, right, and Ryan Harrison embrace after taking out the French Open men's doubles.

While winning a Grand Slam will always be a great moment, the title was was made that much more special for the pair because they won it together.

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CLIVE BRUNSKILL/GETTY IMAGES The pair won in three sets at Roland Garros.

Venus would often stay with Harrison when attending tennis camps before they were professionals and the pair likened their relationship to that of brothers.

"He's been a part of my family. We've been a home away from home for him, considering New Zealand is pretty far away from most tennis training academies, so he was like a brother growing up," Harrison said.

The Kiwi said it was being so close to each other that got them through the final.

"You never know going into a partnership how well it's going to work or what and you're hoping for the best," Venus said.

"What's happened and helped us a lot is knowing each other so well so in those moments like toward the end of the third set there where I was struggling, he stepped up and said 'I've got this' and I know he had.

"It's great to be able to share it with someone so close."

For Venus, the win in the final completes a remarkable run - having never won a set, let alone a match, in three previous appearances at the French Open.

The pair dominated a tight first set regularly putting their opponents under pressure but couldn't convert four break point chances. Venus was forced to dig deep from 0-40 to hold serve late in the set for 6-5 with Venus and Harrison eventually clinching a tight tie breaker 7-5 with the set lasting 51 minutes.

Young and Gonzalez stepped up on serve in the second set and never faced a break point while Venus saved one on his serve as the set went to a tie-breaker.

However, Young and Gonzalez clinched it seven points to four to force a deciding set.

Games went with serve until Gonzalez double faulted to hand the break to Venus and Harrison in the sixth game and the first service break of the match. But Venus was broken straight away after a lengthy seventh game. Young also double faulted to allow Harrison to serve for the match at 5-3 and Harrison closed out the contest on his second match point as Gonzalez hit the ball long to give the Kiwi and American pairing the victory.

To get to the final, Venus and Harrison had come from a set down in each of their five matches and win all six of their matches in three sets.

They had only been together as a team since the start of the clay court season winning the ATP title in Estoril before some mixed results in the lead in to Paris.

The only other Kiwi man to win a Grand Slam doubles title in the Open era is Onny Parun who teamed with Australian Dick Crealy to win the French Open in 1974, beating American's Robert Lutz and Stan Smith in the final.

The last New Zealander to win a Grand Slam title was Judy Chaloner in the women's doubles at the Australian Open in 1979 with Diane Evers.

With Venus's incredible success comes huge financial and status benefits. He is projected to climb as high as 15 in ATP doubles rankings on Monday and will share €540,000 [NZ$850,000] with Harrison.

While Venus scrambled to get into ATP Masters 1000 tournaments in Indian Wells and Miami as alternates earlier this year, he should have no trouble entering the lucrative events in Montreal and Cincinnati in August providing he can find a high enough ranked partner.

Venus will team up with veteran Brazilian Andre Sa for the grass court tournaments in leading up to Wimbledon. Sa has won 11 ATP doubles titles.

Harrison has opted not to play doubles at the All England Club with the format being best of five sets. The American wants to concentrate on his singles where he is ranked 41.