Lake Braddock senior Eric Yoo won the Virginia 6A boys' state singles tennis championship on Thursday. (Kelyn Soong/The Washington Post)

Lake Braddock senior Eric Yoo was struggling with his serve midway through the first set of the Virginia 6A boys’ tennis singles final Thursday afternoon. He had missed six first serves in a row and was facing break point against McLean sophomore Ben Keyser with the set tied at three games apiece.

At the last second, Yoo decided to mix things up. He served underhand to Keyser, who hit his service return into the net.

“I figured if I hit an underhand serve and he missed it, it’d probably mess him up for a few more points after that,” Yoo said. “It was a bit of a trying to get into his head.”

The Johns Hopkins commit went on to the win the game and the set en route to his 6-3, 6-3 victory over the big-serving Keyser on a sunny day at George Mason University in Fairfax.

Earlier in the week Keyser won the 6A North region singles final when Yoo retired with a hip injury down 5-0, but on Thursday, Yoo was the steadier player throughout the match and returned well against the 6-foot-5 Keyser.

W.T. Woodson junior Lexi Merrill won the Virginia 6A girls' state singles tennis championships on Thursday. (Kelyn Soong/The Washington Post)

In the girls’ final, W.T. Woodson junior Lexi Merrill held off a late charge from Robinson sophomore Paige La to successfully defend her title, 6-3, 7-6 (7-2).

For the majority of the nearly two-hour match, Merrill served well and dictated the points, but she began to lose focus up 4-1 in the second set as unforced errors piled up. La led 6-5 before Merrill charged back behind her big serve and backhand winners.

“She was playing really smart and I was giving points away,” Merrill said. “I wasn’t playing my game. I got a little tight and then I kind of settled down. I was like, ‘Okay, fight for every point. She’s going to get to every ball. You’re going to have to hit one more ball than she does.’ I think it worked out in the end.”

Merrill, who will play in Friday’s doubles tournament and Saturday’s team final, has not dropped a set in singles play this season.

In the Virginia 5A boys’ final at Huntington Park Tennis Center in Newport News, Stone Bridge junior Erick Rivas beat Jefferson freshman Ted Zhou, 6-2, 6-2, to avenge his loss to Zhou in the 5A North region finals.

On the girls’ side, Marshall freshman star Reilly Tran engaged in a back-and-forth battle with three-time defending 5A girls’ singles champion Nina Sorkin for almost two hours.

But in the end it was Sorkin, a senior from Deep Run, who prevailed, 6-1, 1-6, 6-4, to claim a fourth straight state singles title and give Tran her first loss of the season.

At Roanoke College, E.C. Glass senior Trent Daly defeated Rock Ridge sophomore Momin Khan, 1-6, 7-5, 7-5, for the 4A boys’ title.

In the boys’ 3A final, Riverside junior Andres Deza, who moved to Virginia from Peru at the beginning of the school year, beat James Monroe junior Marshall Wood, 7-5, 6-3.