Quigley birdied four of the first six holes and Tanaka birdied four of the last six for matching 6-under 64s ' and an eye-popping 13-under 57 best-ball total ' in perfect conditions Thursday on the TPC at River Highlands.
``Today, I wasn't worried about the final score. I was just playing and trying to have fun out there,'' said Quigley, winless in six seasons on the PGA Tour.
Tanaka, a 10-time winner on the Japanese tour, made a 16-foot putt on 16 and a 12-footer on 18 late in the afternoon session for his best round on the PGA Tour.
``This is the first time I've played here,'' Tanaka said of the course. ``Now, I really like it.''
Scott Verplank, Tim Herron, Briny Baird, Jonathan Kaye, Skip Kendall and Japan's Kaname Yokoo shot 65s, and Steve Pate and Kirk Triplett topped a six-player group at 66.
Quigley, the nephew of Senior PGA Tour player Dana Quigley, took the lead at 6-under with a 6-foot birdie putt on the par-5 13th, and saved par on 14 with an 8-footer after driving into the left rough and laying up on his second shot.
The Rhode Island player dropped to 5-under with a bogey from the greenside bunker on the par-3 16th, but got the stroke back with a 17-foot birdie putt on 17 and closed with a scrambling par.
``The greens are good, but they had some pretty tough pins that are hard to get at,'' said Quigley, coming off a 64th-place tie two weeks ago in the Buick Classic.
Verplank made a 35-foot birdie putt on his first hole, the par-4 10th, and holed a 35-foot chip on the par-4 4th, turning a potential bogey into a birdie.
``It was over the waterfall and through the windmill,'' he said, joking about the difficult 7-iron shot from a swale. ``I was hoping to get up and down and actually made it.''
The Ryder Cup player had a double bogey on the par-3 16th after his ball hit the lip of a bunker and rolled into a hard lie.
``There was pretty much no sand in the bottom of the bunker,'' Verplank said. ``I knew it was going to come out a little hot, but it went over the green.''
Herron, trying to earn a spot in the PGA Championship in his home state of Minnesota, birdied the final two holes, holing a 16-foot putt on 17 and hitting a 122-yard shot to 2 inches on 18.
``The ball is starting to go where I was looking,'' Herron said. ``I'm generally a pretty good iron player and a long driver. I just have to get the ball in play.''
Baird, the son of former PGA Tour player Butch Baird, eagled the 284-yard 15th, hitting his drive to 3 feet.
``I hit a driver, which is borderline a little too much club, but it hit in there perfectly,'' Baird said after capping his bogey-free round with a 25-foot birdie putt on 18.
Notah Begay III, the 2000 winner with a River Highlands record 20-under 260 total, was three strokes back at 67 in a group that also included Scott Hoch and Corey Pavin.
Begay, recovering from a back injury, had only his second round in the 60s this year after missing the cut in all 11 of his starts.
Davis Love III, Mark Calcavecchia and Paul Azinger opened with 68s, defending champion Phil Mickelson, Sergio Garcia and Ernie Els followed at 69.
Mickelson bogeyed the first hole and had a double bogey on No. 4. He got a stroke back on the par-3 8th and salvaged the round with birdies on Nos. 16 and 17.
``That was kind of a miracle score for the way I played,'' said Mickelson, second last week in the U.S. Open. ``I didn't strike it that well, but somehow I was able to get up and down and birdied a couple coming in.''
Garcia, regripping the club at address far less than he did at the U.S. Open, had seven birdies, three bogeys and a double bogey.
Playing the back nine first, he reached 3-under with a two-putt birdie from 7 feet on the short par-4 15th, but bogeyed the par-3 16th from the greenside bunker and had a double bogey on 17 after hitting into the water from the left rough.