Shane Bertsch, K.J. Choi among 4 co-leaders at TimberTech

Shane Bertsch, David Toms, K.J. Choi of South Korea and Irishman Padraig Harrington are tied atop the leaderboard after one round of the TimberTech Championship on Friday in Boca Raton, Fla.

The quartet shot 4-under rounds of 67 to set the pace at the penultimate event of the PGA Tour Champions season. They are one stroke ahead of Ken Duke, Marco Dawson and Canada's Mike Weir, who shot 3-under 68 at The Old Course at Broken Sound.

Steve Stricker has already clinched the Charles Schwab Cup title with two playoff events to play, but the rest of the field can still earn a nice season-ending payday by getting into the top 36 in the points standings and qualifying for the season-ending Charles Schwab Cup Championship.

Bertsch entered the week at No. 50 in the standings. If current results were to hold, he'd jump into the top 20 and make the final playoff leg.

Bertsch said he is treating the playoffs as though it's the tour's qualifying school and explained one of his habits that's helping him dial in.

"I've called it my Q-school focus," Bertsch said. "I write ‘Q.S.' on the top of my (scorecard) sometimes."

He was certainly focused for most of Friday, as he drained six birdies over his first 12 holes. But after a string of four pars Bertsch ended his round with consecutive bogeys, dropping him back to the pack.

Choi had by far the most interesting round of the day. He rang up nine birdies but made three bogeys, one double bogey and just five pars.

Harrington, who placed fourth at this event last season, was hurt by an early double bogey but made six birdies, including four on the first nine.

Toms had the cleanest card of the four co-leaders, with five birdies and just one bogey. He won twice in March and, like Harrington, could move into the top three in the Schwab Cup standings with a win this week.

The group tied at 2-under 69 included New Zealand's Steven Alker, who won last year's Schwab Cup and had a hole-out from the bunker for an eagle at the par-5 16th Friday. He was tied with Paul Goydos, Rob Labritz, Justin Leonard, Sweden's Robert Karlsson and Fiji's Vijay Singh.

Defending tournament champion Bernhard Langer of Germany opened with an even-par 71. Stricker is not in the field.