The 70 remaining players will head to Medinah, Illionois for the second stop of the playoffs - the BMW Championship - before the Tour Championship in Atlanta, Georgia. Tiger Woods failed to make the cut after shooting a first-round 75.
The American's self-imposed three-week break from golf in May and June proved just the tonic - on Sunday, Reed won The Northern Trust by a shot in New Jersey.
Both men scored two-under-par 69s, with Reed finishing the tournament on 16 under par.
Reed was at 14-under 199 and will be paired in the final group with Ancer, who had a 68 as he tries to deliver good golf at the right time.More news: Guatemala's new president says "Maybe not Señor Trump"
As the round waned and challengers faded, Reed corrected course with a pair of birdies on 14 and 16 and pared out the final two holes to finish at -2 for the round.
His first round back was with financier and golfing royalty Jimmy Dunne at National Golf Links, and he drove the short par-4 first hole and made a 6-foot putt for eagle.
Patrick Reed loves himself a brawl, and while he avoided the one that almost took place off the course, he came out on top of the one that happened at Liberty National Golf Club on Sunday afternoon. "It's been a while".
While DeChambeau contended that he was being unfairly singled out, he admitted to taking too long at times and said he was in favour of penalty strokes being handed out. He struggled after winning The Masters. "I feel I'm not very far", he said.
After a miserable run of form earlier in the year he made a decision to take a proper break in May. I've always wanted to compete to win.More news: 'Tennis grandmum' Serena Williams has still got it
"It's going the right direction", he said. "I'm trying not to think about that that much".
Reed finished at 16-under 268 and won for the seventh time in his career on the PGA Tour. He's now converted five of his seven 54-hole leads into victories.
Next week in Chicago at the BMW Championship, there guarantees to be more exciting golf just like we saw this past weekend in NY.
"But what better place to do it than here, having the Statue of Liberty in the background, the Presidents Cup was here in 2017 and hearing "Captain America" and "USA" all week, it was a good time to get a (win)". "Making it into the Tour Championship is huge".
"I didn't feel that great early on. I might have gotten into a situation where I was working too hard". I'll have three or four weeks off, and I want to fix it. The third place finish lifted him from 102nd in the FedEx Cup Standings all the way to 29th (the biggest jump this weekend), securing a spot at the BMW Championship at Medinah Country Club, in IL. There are nine players within four strokes of Reed, including past FedExCup champions Justin Rose, Rory McIlroy and Brandt Snedeker.
As Reed's 48-spot jump in the standings was impressive, two other players jumped significantly more spots that Reed. Even his beloved Captain America persona suffered from his poor Ryder Cup showing and subsequent attempts to pin the blame on skipper Jim Furyk and frequent playing partner Woods. There's pressure to play against the top and any one can win.More news: Questions Mount Over Epstein's Death in Custody