Game, set, marriage.

Tennis pro Sloane Stephens and U.S. soccer forward Jozy Altidore on Monday announced their engagement on Instagram.

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The 2017 U.S. Open champion posted a photo of her and Altidore smiling with a caption reading, “Forever yes.”

“Forever starts now,” wrote Altidore, 29, on his own post along with a photo of Stephens flashing her engagement ring.

Altidore and Stephens, 26, have reportedly dated for several years, but the tennis champion told the New York Times in September 2017 that they've known each other since fifth grade.

“I don’t think there’s been a more positive person in my corner that I’ve had,” she told the Times, crediting Altidore with supporting her through a bad foot injury that kept her from competing for 11 months.

Aside from winning a Grand Slam title that summer, Stephens was also the 2018 French Open runner-up and a member of the 2017 championship U.S Fed Cup team. She is currently ranked No. 8.

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Altidore made his professional debut at age 16 with the New York Red Bulls. After stints with several teams overseas, including Sunderland A.F.C. and Hull City in the English Premier League, he joined Toronto FC in Major League Soccer in 2015.

The striker has also been a prominent piece of the U.S. national team, scoring 41 goals — the third most in the team’s history — in 110 international appearances since his debut in 2007. He famously scored against a dominant Spain team in the 2009 Confederations Cup semifinals to see the U.S. advance to the finals against Brazil.

His last cap for the Americans was in October 2017, when a loss at Trinidad and Tobago ended their road to the 2018 World Cup in Russia.