Canadian Stephen Ames in contention at Charles Schwab Cup Championship

Bernhard Langer squatted to tee up his ball instead of bending at the waist. Lining up putts looked like he was doing calf stretches against a wall, more of a chest-high view than ground level.

By the sixth hole, the 64-year-old gave up on retrieving the ball from the hole altogether, asking caddie Terry Holt to do it for him.

Any other tournament, Langer would have withdrawn. He nearly did anyway, even with a sixth Schwab Cup on the line.

"It was the most pain I've had playing golf in 30 years," Langer said. "It was pretty bad. I told Terry I probably shouldn't even be here right now, but somehow I started praying out there that the pain would subside and I managed to make it through, but it's not good. Not sure I can do this for four days. Hopefully, I'll feel better tomorrow."

Vancouver native Stephen Ames finished his first round two strokes back at 4-under 67.

Mickelson had seven birdies and a bogey to match Jim Furyk and Kirk Triplett for the lead in the PGA Tour Champions season finale at Phoenix Country Club.

The German star felt tightness in his back during Wednesday's pro-am and woke up in pain on Thursday. He was able to loosen it up some during warm-ups, but the pain got bad again while putting before his round.

Despite walking with slight hunch, Langer still managed to make three birdies to offset a bogey on the front nine and had two more on the back. He caught a break when his third shot on the par-5 18th hole caught up in the rough before rolling into the water. He then got up-and-down for a par.

"I was this close from pulling out on the second hole," Langer said. "Felt a lot of twinges, lower back spasms. Staying in my shot, staying down, felt like I wanted to straighten up a lot. Hit some poor shots out there, but somehow scraped it around."

Mickelson big fan favourite in return to Arizona

Furyk, who can win the Schwab Cup with a victory this weekend, had four birdies in his final five holes and seven overall playing in the final group with Langer. Els had four birdies to shoot 68 and Jimenez couldn't get much going, finishing with two birdies in a 70.

"Good, solid round. Not a lot of mistakes today," said Furyk, who played at the University of Arizona in Tucson. "Hit a couple bad putts on the back nine at 12 and that bothered me a little bit. A couple bad drives at 17 and 18, but overall I hit the ball extremely well today."

Mickelson opened with a birdie on the par-5 first hole and had four more on the back nine. He wowed the crowd by hitting a 192-yard 5-iron from a fairway bunker to the fringe on the par-5 18th hole before lipping out his eagle putt. A tap-in birdie capped a 4-under 31 back nine.

"The course is in such pristine shape and to play a golf course where you can play some holes aggressive, there are a few parallel fairways, I like that," Mickelson said. "It allows me to be a little bit more aggressive and play to some safer areas, and then I'm able to take advantage of some short iron play, so I ended up making some birdies."

Fred Couples was a stroke back at 66 with David Toms, Brandt Jobe, Steven Alker and K.J. Choi.

Alker is coming off a victory Sunday in Florida in the TimberTech Championship. The New Zealander had no status when he turned 50 in late July. He qualified for the Boeing Classic in August and had top-10 finishes every week to keep playing to become eligible for the postseason.