(CNN) -- For the second straight day at the Deutsche Bank Championship, a player who won a major this season hit a 63.
This time it was U.S. Open champion Justin Rose, not British Open titlist Phil Mickelson.
Rose hit four birdies on the front nine and four on the back nine for the eight-under 63 at TPC Boston to move into contention following his second round.
He was four shots behind clubhouse leader Sergio Garcia.
"It came out of nowhere," Rose was quoted as saying by the Golf Channel. "I felt kind of lethargic, felt like I was plodding around and then all of a sudden I looked at the scoreboard and I was doing okay."
Rose is hoping he can carry the momentum into the final two rounds.
After capturing the U.S. Open in June to deliver on the promise he showed as an amateur, the Englishman missed the cut at Muirfield and hadn't finished in the top 10 prior to The Barclays in New Jersey last week.
Even though he tied for second, Rose missed a birdie putt that would have given him the title.
Garcia, like Rose, was a player of potential when younger but hasn't yet claimed his maiden major.
The Spaniard, though, has thus far performed well in Boston. He followed up his 65 with a 64 on Saturday, despite carding a double-bogey at the 14th hole.
Garcia decided to play this week and add to his schedule to make sure he's in the field for the third of four FedExCup playoff tournaments, September's BMW Championship in Illinois.
"It was touch and go if I was going to make the BMW without playing here," Garcia told reporters. "We decided to come here and make a little bit of an extra effort of playing five weeks in a row, which I don't usually enjoy very much."
Mickelson, the overnight leader, slipped five shots behind Garcia.
He started well, collecting two birdies without dropping a shot on the front nine. On the back nine, however, Mickelson registered two bogeys and a double bogey. He needed birdies on the final two holes to complete his day at par-71.
Tiger Woods, the world's top-ranked golfer, struck five birdies and a single bogey for a 67 but trails Garcia by six shots.