Playing in his first Grand Slam main draw, Francis Tiafoe, a Riverdale Park native, won his firstmatch in doubles, teaming with fellow 16-year-old Michael Mmoh to beat Victor Estrella Burgos and Teymuraz Gabashvili, 6-3, 6-4.

Tiafoe earned a wild card to U.S. Open singles qualifying, but lost to Tatsuma Ito last week. He got good news when he found out he got a wild card into the doubles main draw when scrolling through Twitter on Saturday night, hurriedly packing his things to come to New York a week earlier than he had planned.

Tiafoe will play in the U.S. Open junior championships next week and said the experience of playing doubles boosts his confidence.

“Being in this environment helps,” Tiafoe said. “We feel like we’re someone here, just being around the pros and being in the same locker room as all of the greats.”

V. Williams advances

Venus Williams, the No. 21 seed, advanced to the third round for the first time since 2010 with a 6-1, 6-4 win over Timea Bacsinszky and next plays No. 13 seed Sara Errani.

“I’m happy,” Williams said. “Finally, I did something I couldn’t do in the last couple of years. That’s good stuff.”

Stephens ‘shaky’ in loss

Despite another disappointing early exit for Sloane Stephens, the young American said she’s “not going to dwell” on her 5-7, 6-4, 6-2 second-round loss to Johanna Larsson.

Playing at Arthur Ashe Stadium, Stephens had a 3-0 lead in the second set before unforced errors doomed the No. 21 seed. She had 63 in the match to Larsson’s 30.

“Things just got a little shaky,” Stephens said. “Obviously she played some good games after that. At the start of the third set, I tried to just put it behind me and came out swinging. She played a solid game. . . . I had many opportunities, but just couldn’t convert.”

Stephens burst onto the international scene when she upset Serena Williams in the 2013 Australian Open, but she’s had mixed results since. She advanced to the fourth round of the first two Grand Slams of the year, but lost in the first round of Wimbledon. She hasn’t made it past the round of 16 since then.

“I haven’t had that great of a season,” Stephens said. “I’m not going to dwell on it. There is always room for improvement. Everyone has their ups and downs. Everyone goes through times like this. I’m not the first person and won’t be the last. I’m looking forward to the next tournament. And that’s all I can really do, just look forward.”

No. 4 Radwanska loses

Wednesday wasn’t kind to fourth-seeded Agnieszka Radwanska, who fell to China’s Shuai Peng, 6-3, 6-4.

Radwanska, who recently won the Rogers Cup in Toronto, has not had good results in the U.S. Open, never advancing past the fourth round in nine appearances.

“I really want to know the answer, then maybe I will find a way to play better here and just try another way to be in the second week,” Radwanska said. “There is just something here that I can’t really pass those rounds. . . . Hopefully, one day I will do it.”

Sharapova rallies to win

No. 5 seed Maria Sharapova struggled early against Alexandra Duhlgeru, but rallied for a 4-6, 6-3, 6-2 win.