SEAL BEACH — LeBron James probably can empathize with Newport Harbor High junior Reese Stalder.

James missed the final few minutes of Game 1 of the NBA Finals on Thursday night, after cramping up. On Friday afternoon at Seal Beach Tennis Center, Stalder's body also failed him at the worst possible moment at the CIF Southern Section Individuals boys' tennis tournament.

At 6-5 in the second set, Stalder was serving for the match against top-seeded Michael Genender of Harvard-Westlake. He was points away from one of the best wins of his career.

On a second serve at 30-40, Stalder fell to the ground, and it wasn't in celebration. He was cramping up in his left quadriceps.

"I served, and when I landed on my left foot, my left quad just kind of went under me," Stalder said. "It was cramping. Each [point] it kept getting worse."

Stalder wasn't himself for the ensuing tiebreaker that Genender won, and for much of the third set. The result was a disappointing 6-4, 6-7 (3-7), 3-6 loss in the CIF Individuals quarterfinal match.

Earlier Friday, Stalder beat BYU-bound Alta Loma senior Victor Brown, 6-4, 6-4, in a round of 16 match. Brown was a CIF Individuals finalist last year.

Several people came up to Stalder after the match against Genender and congratulated him for sticking it out in the third set, when he could hardly put any pressure on his legs and he limped around the court. Stalder said that midway through that last set, his right calf also started giving him issues. He fell behind 5-1 before making a bit of a rally, and he saved two match points. But he double-faulted twice to end the match.

"It just kept getting worse," Stalder said. "I felt pressure to have to just whale away on my shots ... the result doesn't bother me too much. I play like that and I don't cramp, I say I win that match. I'm not too bummed. I kept my composure ... overall it was a good match for me. I'm still pleased with how the day went."

Stalder, ranked No. 9 in the Southern California boys' 18s and the Sunset League runner-up, frustrated top-ranked Genender for much of the match. He broke Genender's serve to take a 4-3 lead in the first set. Genender, the Mission League champion who helped Harvard-Westlake reach the CIF Southern Section Division 1 title match, let his emotions get the better of him.

Stalder hit a winner on a return of serve, but Genender thought the serve was out. However, Stalder never called it out. Genender appealed to a referee, who said he didn't see if Genender's serve was in or out.

"What are you standing there for if you're not watching?" Genender yelled to the referee, who did come on the court after the point. But Genender was broken in the game four points later. Stalder eventually was able to serve out the set.

"I was just taking the ball early on the rise, serving big and just ripping," Stalder said. "It was working really well; I was in control. I thought I was out-playing him, then unfortunately [the cramping was] out of my control. Nothing I could do."

Stalder's serve was broken in the second game of the second set, but he immediately broke back. Stalder's Newport Harbor teammates, David Schaefer and Phillip Vu, roared their approval. After saving a set point to hold for 5-5, Stalder broke Genender's serve, setting himself up to serve for the match.

Stalder fell behind love-40 in that game, won two points but then double-faulted as he fell to the ground and the cramping began.

"He was serving huge," Genender said. "He was hitting his spots, and I couldn't read where it was going. I was trying to mix up my positioning on the returns, and I really had no answers for him. That was probably one of the best serving displays in two sets I've ever played against. It was just a barrage ... I was definitely on the ropes.

"I got lucky to get that break back, really. I hit a couple good shots, a couple of returns, he double-faulted. Maybe I was just a little bit more relaxed, thinking, 'You know what, it's going to be over soon anyway, maybe just take a couple of shots.' Maybe that made the difference, so that those returns I wasn't making earlier were going in. I'm thankful for that."

Earlier Friday, Stalder earned a good victory over Brown. He broke Brown's serve in the first game of each set, the only breaks of the match.

"He did a good job of disguising his forehand," said Stalder of Brown, a lefty who was undefeated this year and won the Baseline League title. "He'd get really wide angles on it. It was tough to get a beat on it, so I was trying to keep it to his backhand."

Genender will play University High senior Drew Dawson in a CIF Individuals singles semifinal Saturday at 11:30 a.m. No. 2-seeded Austin Rapp of Palm Desert will play Chase Mascorini of Dana Hills in the other semifinal.

Top-seeded Robert Carter and Ryan Cheng of San Marino will play Connor Rapp and Sebastian Gomez of Palm Desert in one doubles semifinal, with University's Arash Hafezi and Eric Tseng meeting Ricky Kurtz and Ryan Dugan of Santa Margarita in the other.