SAN DIEGO — The shot was worthy of a much louder celebration.

Camilo Villegas was in a bind on his second hole of the Buick Invitational, hitting his tee shot to the right and leaving himself some 50 yards to the hole with a bunker limiting his view to the top portion of the flag. With a new 63-degree wedge, he hit a perfect flop toward his target and wound up with an eagle.

"My caddie said, 'It went in.' Early in the round, not much of a reaction," Villegas said.

There wasn't much of a crowd at Torrey Pines on Thursday, when Villegas tied his personal best with a 9-under 63 on the easier North Course to build a three-shot lead over Davis Love III and Aaron Baddeley. Across the way, Phil Mickelson patched together enough great par saves for a 70 on the South Course that put him in good shape.

One reason for the thin gallery was the absence of the four-time defending champion, Tiger Woods.

Now that might be reason for Villegas to celebrate.

The 27-year-old Colombian picked up his first PGA Tour victory last year in the BMW Championship, where Woods was the defending champion but unable to play because of his season-ending knee surgery. A week later, Villegas won in a playoff at the Tour Championship, where Woods also was the defending champion.

The Buick Invitational is the third straight PGA Tour event that Woods is not able to defend.

Is it any surprise to see Villegas' name atop the leaderboard?

"It's very early in the week," Villegas said. "I mean, I played one round. I played great today."

Even so, this is one place none of the players particularly miss the world's No. 1 player. Woods is the four-time defending champion of the Buick Invitational, with six victories in all.

Villegas didn't fare too badly himself, although it will take another round to sort out the real contenders. Few other courses have such a disparity in scoring — the South hosting a U.S. Open and stretching over 7,600 yards, the North a pedestrian 6,915 yards with hardly any rough to punish errant shots.

The average score on the North was 71.73, while the South played to an average of 75.37.

That's where Villegas is headed today, with rain that began falling late Thursday afternoon in the forecast the next two days. He realizes he could face thicker rough, firmer greens — and he doesn't seem the least bit bothered.

"Who knows, man?" he said. "Just go out there and hit some shots."