Phil Mickelson withdraws from Farmers Insurance Open

Phil Mickelson was eight strokes behind second round leader Jordan Spieth. Tiger Woods was nine shots behind Speith at Torrey Pines. Phil Mickelson said he withdrew after wrestling with back muscle pain.

Jordan Spieth showed maturity beyond his 20 years to take a one-shot lead at the Farmers Insurance Open by shooting a 9-under 63 on Friday.

Spieth played his round on the easier North Course at Torrey Pines while second-placed Stewart Cink had a 71 on the South.

Spieth achieved the rare feat of upstaging his playing partner Tiger Woods, who has won eight tournaments at the course, including last year's event and the 2008 U.S. Open. Woods, in his first competition in six weeks, did not make birdie on any of the par 5s for the second straight day, and a three-putt bogey on the par-5 ninth hole on the North gave him a 71.

Woods was nine shots behind, but at least he was still in the tournament, unlike long-time rival Phil Mickelson, who completed the second round but then withdrew due to back muscle pain.

Mickelson shot a 1-over 73 on the South Course in the second round, leaving him eight strokes behind Spieth. Mickelson said after the round that he feared getting into bad habits by altering his swing to keep his back from hurting.

His management company released a statement late Friday evening that Mickelson had decided to withdraw. He is scheduled to defend his title next week in the Phoenix Open.

It was the first time Spieth has played with Woods in a tournament, and he seemed to relish it.

"Any time you can shoot a lower score than a 66 or 65 and you can really get it deep and be in a zone and not worry about what your score is ... that's special," Spieth said. "That's proving that I can play my best golf when it matters on a PGA Tour venue. Each time you can do that, you get more and more confident that you can do it more often."

Spieth was at 10-under 134 and will be in the last group Saturday with Cink and Nicolas Colsaerts, who shot 67 on the South and was two shots behind.

"I'm looking forward to playing with Jordan. I've never seen him hit a ball, so that will be fun," Cink said. "It's always exciting to see the young guys play. I'm playing really well."

The final two rounds will be on the South, which is about 600 yards longer and on Friday played more than 4-½ shots harder.

"The kid's got talent," Woods said of Spieth. "He hits it a long way, phenomenal putter. He made a boat load of putts today from the 10- to 20-foot range. He was pouring them in there."

That wasn't the case for Woods, whose only birdies came on his opening hole and on his sixth hole.

"I was just a fraction off, and at this level and on golf courses like this, if you're just a fraction off it doesn't take much, especially as tight as the North Course is," Woods said. "I had so many balls that landed in the fairway that went in the rough. Now I can't be aggressive, I've got to play conservative into some of these flags."

The cut was at even-par 144, and 83 players advanced. There will be another cut to top 70 and ties after the third round.

Woods wasn't ruling himself out just yet. He remembered the time he made the cut by two shots in 1999, and then had a 62-65 weekend to win by two shots. But that was before the South Course was lengthened. This year, no-one had better than 67 over the first two rounds on the South.

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