The pair on Saturday won 7-6 (5), 6-7 (4), 6-3 against Santiago Gonzalez and Donald Young.
Ryan Harrison and Michael Venus won their first Grand Slam tennis title with a victory in the men's doubles final in the 2017 French Open here.
The US-New Zealand pair on Saturday won 7-6 (5), 6-7 (4), 6-3 against Santiago Gonzalez and Donald Young in two hours and 14 minutes, reports Xinhua news agency.
"You always dream of winning a Grand Slam every time you're playing as a kid. You idolise people who win Grand Slams. You picture yourself in those moments. It feels a little surreal," said Harrison, adding that Venus felt like a brother to him.
"He's been a part of my family. He was like a brother growing up. He taught me how to drive and how to do a lot of things," he recalled.
The winners finished five aces and five winners, both bettering their opponents by two.
Harrison, who also played in the singles event, hoped that he could benefit a lot from the doubles Grand Slam title.
"I'm hoping this can lead into singles success as well, and I know my confidence will be very high coming off this," he said.
Earlier on Saturday, Latvian underdog Jelena Ostapenko won her maiden Grand Slam trophy with a 4-6, 6-4, 6-3 victory over the third-seeded Simona Halep in the women's singles final.