STANFORD, Calif. (AP) Southern California's Steve Johnson advanced to the NCAA men's singles final when his opponent retired in the middle of the second set Sunday following a disagreement with the chair umpire.

Top-ranked Johnson was leading 7-6 (4), 3-2 and had a break point when Virginia's Michael Shabaz hit a ball out of the stadium and was penalized a point. Shabaz walked over, shook the umpire's hand and left the court.

I'm in shock,'' Virginia coach Brian Boland said.I consider this the lowest point of my 15 years as a collegiate head coach. I've known Michael four years and he's never quit on a match or walked off the court.''

Shabaz wasn't made available to the media after the match. He issued a statement through the school about 90 minutes after he retired.

It was an unfortunate way for the match to end,'' he said.Take nothing away from Steve Johnson, as he is a terrific player and we have always had a great relationship. It was an emotional decision in a highly contested match. I'm sorry the match ended under these circumstances.''

Johnson beat Shabaz in the finals of the team tournament and said he had a lot of respect for him.

He's a tough competitor,'' said Johnson, who will play Tennessee's Rhyne Williams in the final.I'm still not sure what happened. I've never had that happen in my life.''

Williams beat Volunteers teammate and best friend Tennys Sandgren 6-3, 3-6, 6-0 to advance.

Shabaz, a senior, helped lead the Cavaliers to the brink of a national title in each of the past four years. Virginia was the top-seeded team entering the tournament all four years and reached its first national final Tuesday, losing to the Trojans.

He's a good kid,'' Boland said.I cannot believe Michael made that decision regardless of his disagreement. I know his emotions were at a high point but you are never justified in quitting a tennis match no matter the circumstances. This, to me, is harder than the team loss.''

Johnson became the first Trojan to reach the final since Cecil Mamit won the title in 1996.

Having never seen a semifinal or final before, this is amazing,'' Johnson said.There are tons of people here and it's a great place to play.''

Williams and Sandgren have known each other since playing in a junior tournament when they were little. The doubles partners (20-4 as a team this year) wore each other's jerseys to honor their friendship.

Once we were on the court I was fired up to play the match,'' Sandgren said.I knew it wasn't going to affect us. We knew not to take it personally. I'll be his biggest fan.''

The sophomores lived together during the school year and were roommates during the two-week stay in the area.

We went through the same routine,'' Williams said.It was the same as it ever was. There was no tension.''

California's Jana Juricova, the top-ranked women's player, survived a three-hour marathon, beating Stanford's Nicole Gibbs 6-7 (5), 7-5, 7-6 (2) to reach the championship.

I think it's one of the most competitive matches I've ever played,'' Juricova said.She's a great player and a great competitor. I knew I had to play my best game to beat her. I had to be mentally tough. The crowd was great. It was a fun match to play.''

Gibbs won consecutive matches against top-10 players, including teammate Hilary Barte, to reach the semifinals.

She came up with big serves in general,'' Gibbs said.I wasn't feeling as confident as I'd like in my serve game.''

Juricova will face Stanford's Stacey Tan in the women's final. Tan advanced after Florida's Lauren Embree retired with blisters on her feet. They split the first two sets.

At the start of the second set I just tried to remind myself to work through every point and see how things go,'' Tan said.I think I pulled through a couple of key points.''