SINGAPORE — Lorena Ochoa left Annika Sorenstam and everyone else behind in the HSBC Women's Champions. Then was at a loss for words to explain the blowout victory.

"Sometimes there is just no explanation," Ochoa said yesterday after beating Sorenstam by 11 strokes in her first start of the season. "It just happens and it was a great win for me. Everything came together at the right place."

Competing for the first time since winning the ADT Championship in November for her eighth 2007 victory, Ochoa finished at 20-under 268 on Tanah Merah's Garden Course. The top-ranked Mexican star earned $300,000 for her 18th career LPGA Tour victory.

Ochoa entered the final round with an eight-shot lead, and steadily built on it through three rain delays. She passed the down time by chatting with her brother.

"It was more mentally a tough day than physically. You needed to be patient and not to worry too much, and hit the ball with precision," Ochoa said.

Sorenstam won the B-flight, shooting a 71 for her third straight top-four finish. Slowed by neck and back injuries last year, she won the season-opening SBS Open at Turtle Bay for her 70th LPGA Tour title and first since September 2006, then finished fourth last week in the Fields Open at Ko Olina.

"I'm glad it's over now, just because I'm worn out. It's been tough," Sorenstam said. "I've played really well, just haven't performed well on the greens."

Paula Creamer, the Fields Open winner, shot a 73 to finish third at 7 under. Laura Diaz (71) was another stroke back in the first-year tournament, and Karrie Webb (74) and Stacy Prammanasudh (71) followed at 5 under.

"It was an up-and-down day with the on-and-off-again rain, but I never really got any momentum," Creamer said. "But it's the same for everybody out there and you just kind of have to grind through it."

In an event where only 13 players finished under par, Ochoa opened with rounds of 66, 65 and 69 to take an eight-stroke lead over Sorenstam and Creamer into the final round. Ochoa missed a chance to break Cindy Mackey's 72-hole record for margin of victory of 14, but topped her own mark of 10 in the 2006 Tournament of Champions.

"Sometimes you can play your best and someone else does something better than you, and sometimes you can just play OK and win," Ochoa said. "Sometimes you can get away with a tournament, but this week for some reason I was the only one that — I played consistent and some other players struggled a little bit.

"Sometimes it happens that you take a big lead and you feel comfortable and you keep going, and today that was the case. It was just great because I also had pressure. I wanted to keep the pace. I didn't want to make mistakes. I wanted to win by more than eight, which was my lead yesterday. It was good today."