Quinney and Tommy Gainey shot 7-under 63s on Thursday to share the lead after one round in the Wyndham Championship.
Quinney had eight birdies, including five in a row early in his round, to start strong in his last chance to qualify for golf's postseason.
Gainey had five birdies and an eagle in matching his career-best round. Both players are chasing their first PGA Tour victory.
Stuart Appleby had a 64. Ten players — Paul Casey, Carl Pettersson, Ernie Els, Jason Bohn, Jimmy Walker, Tim Herron, Lee Janzen, Jim Furyk, Vijay Singh and George McNeill — shot 65s during another low-scoring day at Sedgefield Country Club.
Quinney arrived in 215th place in the FedEx Cup standings. A win — and the 500 points that accompany it — would put him in The Barclays.
"The only chance I get in the playoffs is probably winning this week, and coming with the attitude of 'all-in,'" Quinney said. "Basically, just push all your chips in, and this is what I got."
A year ago, a close-but-not-enough finish on this course left Quinney outside the playoff field. He wound up in 126th place, falling short of the postseason by three points.
He spent most of the first day of his return to the par-70 Sedgefield layout near the top of the leaderboard after his early flurry of birdies.
Starting on the back nine, Quinney birdied Nos. 12-16 to move to 5 under. After a bogey on No. 18, he added three more birdies on his final nine holes and closed by sticking his 140-yard approach shot within 3 feet and sinking that putt for his eighth birdie.
"It's my last chance, and don't hold back, try to get out of my own way," Quinney said.
Quinney, who has conditional status on the tour, is playing just his 11th tournament of the year.
"Once you do get in, you put a little pressure on yourself," Quinney said. "It's been frustrating. This is my first year I've been non-exempt for five years, and so I think you just expect it to be somewhere else, and it's a struggle mentally to fight that. I still got the game. I just need the opportunities and not to get in your own way and try to force things."
Gainey caught him during the afternoon, with four birdies and the eagle coming during the South Carolina native's front nine. He moved to 7 under with a birdie on the par-4 13th, but ran into trouble on No. 15 when he sent his tee shot into a creek and closed his round with five pars.
"I hit it terrible off the tee, hit my irons really good, made a lot of putts, but I left quite a few shots out there, so I've got to definitely work on the tee ball here, because it's starting to really frustrate me," Gainey said. "Any time you play and shoot 63 ... when you have no blemishes on a golf course like this — or any golf course, for that matter — it's a good day."
Gainey — who's at No. 40 on the points list — is safely in the playoff field.
Some others here this week aren't quite that secure.
Once again, the prevailing storyline was the list of players who came in search of a push into the playoffs. The Wyndham annually marks the final chance to crack the top 125 on the points list and qualify for the postseason, which starts next week in New Jersey.
"I said to the guys, 'My playoffs started this week. If I don't play well this week, I'm not advancing,'" Els said. "Most of the other guys have four playoff events. I have five. I feel like I need to do well (to go to) The Barclays and keep going. It's hard not to think about it. There's quite a bit of pressure on us guys lower down the field. We need to perform well."
Fabian Gomez delivered the shot of the day — a double eagle on the par-5 No. 15. His 5-wood shot from 250 yards out went into the hole on the fly for the tour's third albatross of the year.
And Furyk had two eagles in a span of four holes, his second multi-eagle round this year.
Indeed, low scores once again were the norm at the Donald Ross-designed course. Since the tournament moved back here in 2008, two of the three winners have finished at 20 under or better.
"My caddie said 5 under every day is sort of the goal," Casey said.