Portugal Colonial - Taiwan's Yu grabs one-stroke lead at Torrey Pines

Yu, a former world amateur number one who missed four months after suffering a torn meniscus in his left knee last February, edged a stroke clear of world number six Patrick Cantlay and Japanese rookie Ryo Hisatsune with his bogey-free effort at Torrey Pines North Course, one of two in use for the tournament.

Both Cantlay and Hisatsune had eight birdies with one bogey on the North Course.

"I was just trying to play my best today, just trying to hit a lot of fairways, trying to make as many putts as I can," Yu said. "Greens a little bumpy, but I'm just trying to hit the best stroke I can out there, which I did today."

On a day when staying out of the dense rough still wet from rain early in the week was key, Yu hit 12 of 14 fairways in regulation and 17 of 18 greens.

He said keeping it in the fairway was a priority, and after finishing tied for third after a final-round 63 at La Quinta on Sunday he was confident he could do so.

"I've been hitting very good," he said. "I don't have to try to hit like my maximum distance out there, I just have to hit a lot of fairways. That was just the plan today, and if I hit a fairway, like ball-striking's been pretty decent for me, too."

Hisatsune also said finding the fairway was key, and led to a "comfortable" day, while Cantlay said the rain-soaked course allowed a more attacking style.

"I think it allows you to take on a few more of the hole locations just because the ball's going to hit and stop," Cantlay said. "I think overall the scores will be lower this week because of how wet it is."

There was plenty of pressure on the leaders with 17 players within three strokes of the lead.

Former Masters champion Hideki Matsuyama headlined a group on 66 that also included Ireland's Shane Lowry, Belgium's Thomas Detry, England's Aaron Rai and Argentina's Alejandro Tosti.

Matsuyama rattled in an eagle putt at the par-five fifth hole and Lowry made six of his nine birdies in his last eight holes to climb the leaderboard.

"Made a couple of sloppy bogeys, but after that I felt like I played some lovely golf on the way in, hit some lovely shots and kind of rolled in the putts I needed," said Lowry, who capped his round with three straight birdies.

Another group of nine on 67 included Denmark's Nicolai Hojgaard and American Nick Hardy, whose five-under efforts were the best of the day on the tougher South Course, the US Open venue that will host the third and final rounds on Friday and Saturday.

Yu said his game plan wouldn't change when he tackled the South Course on Thursday.

"My plan was just trying to hit a lot of greens and trying to hit a lot of fairways and hopefully make some putts -- that's the plan for tomorrow," he said.

H.Silva--PC