Tiger Woods vowed to "keep fighting" and ruled out using injury as an excuse after the worst round of his professional career left him staring at a last-place finish at the Waste Management Phoenix Open.

While Scotland's Martin Laird surged into a two-shot lead at ten under par by the halfway point, Woods was left propping up the leaderboard with Michael Hopper on 13 over.

Padraic Harrington missed the cut by five shots after a quadruple bogey on the 18th hole sealed a miserable 78 and left him seven over par.

14-time major winner Woods went round TPC Scottsdale in an 11-over-par 82 for a 13-over total. Hopper, at 12 over, had two holes remaining when play was ended by darkness.

Woods' round was one shot worse than his previous high at the 2002 Open Championship at Muirfield, on a wet and windy Saturday in East Lothian.

While rain was falling in the desert on Friday it was no excuse for Woods, whose short game in particular let him down badly as the 39-year-old recorded a triple, two doubles and six bogeys alongside two birdies.

"It's golf," Woods told a press conference televised by the Golf Channel. "We all have days like this. Unfortunately mine was in a public setting but we all have days like this and we take the good with the bad.

"Even on bad days like this, just keep fighting because on the good days you've to keep fighting as well."

Woods missed the cut at the US PGA Championship in August, his last official Tour event, and then withdrew from contention for Ryder Cup selection as he continued to recover from back surgery.

But he stressed that he was physically fine and injury was not the cause of his poor effort, instead admitting the transition from previous coach Sean Foley to new swing consultant Chris Como is taking some adjusting to.

"Overall swing-wise my attack angle was much steeper with Sean and now I'm very shallow, so that in turn affects the chipping," he said.

"I'm not bottoming out in the same spot. It's a different spot."
Starting from the 10th hole, a bogey on 11 and a double-bogey on 14 and a triple on 15 left Woods, who has fallen to 47 in the world, six over for the day after as many holes.

Two consecutive bogeys got him to the turn in 44, matching his worst nine-hole score at the Memorial Tournament at Muirfield Village in 2013.

After another double-bogey, a birdie and two further bogeys, a birdie on eight meant Woods could avoid hitting a new low with a par on the par-four ninth.

But after leaving himself with 11 feet, he missed left to make unwanted history.

At the other end of the leaderboard, Laird enjoyed a 66 featuring six birdies, including three in succession from the 15th, and marred only by a closing bogey.

Daniel Berger was second at eight under with Justin Thomas seven under, the two tour rookies each playing on sponsor's invitations.