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.
Langer arrived in the desert as the prohibitive favorite to win his sixth Schwab Cup, joining Furyk, Ernie Els and Miguel Angel Jimenez as the only players with a chance to win the season championship. Langer's scenarios for winning his fifth Schwab Cup in seven years ranged from winning the Schwab Cup Championship to 35th, depending on how the other contenders finish.
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.”
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 was a big fan favorite in his return to the Valley of Sun, where he starred at Arizona State. Lefty is a part-time player on the PGA Tour Champions while still playing on the regular tour, winning three of his five starts on the senior circuit.
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.
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