Jake Knapp takes control at CJ Cup Byron Nelson

DALLAS: Jake Knapp's second straight 7-under-par 64 vaulted him into the lead at the CJ Cup Byron Nelson on Friday in McKinney, Texas.

Starting his round on the back nine at TPC Craig Ranch, Knapp rolled in four birdies on each side, finishing with a two-putt birdie at the par-5 ninth to get him to 14-under 128.

That was enough for a one-shot lead over Troy Merritt, who fired a 9-under 62 Friday, and first-round leader Matt Wallace of England (66).

Kelly Kraft (66) is in fourth at 12 under and Keith Mitchell shot a 65 to join a tie for fifth at 11 under with Davis Riley (67) and Canada's Taylor Pendrith (67).

A 30-footer for birdie at the par-4 16th launched a run of three straight birdies to close Knapp's first nine. He rebounded from his only bogey of the day with a 32-foot birdie putt at the par-3 fourth to reclaim the lead.

"Early on in the year felt like I was putting well, and for the last month or so the stroke felt the same and ball wasn't going in the hole," Knapp said. "So just put a little bit more of a premium the last couple weeks on green reading. Yeah, nice to see a few more going in."

Knapp, 29, is a PGA Tour rookie who broke through for an unlikely win at the Mexico Open in February. He tied for fourth the following week at the Cognizant Classic, but his results spiraled downward after that. "I think I just got a little tired," Knapp said. "I think mentally it was just a lot going on, and I wouldn't say necessarily life changing, just everything got busier and days got longer. It was just a bit of an adjustment. Didn't feel like I had the same energy throughout the day in some of those weeks, which was kind of a bummer. "Decided to take last week off and give myself a good reset at home and work on some things I've been struggling with, and feel like it's working out this week so far."

Merritt also started on the back nine and made the turn in 3-under 32, then picked up steam on the front nine. After four more birdies, he drained a 16-foot eagle putt at No. 9 to secure the low round of the day.

"After I three-putted 12 for bogey, I hit a 6-iron in 206 and went over the green on 13 and then I chipped in (for birdie)," the two-time PGA Tour winner said. "I would say getting that bogey back right away on a tough hole like 13 was probably the momentum -- or kept the momentum going. And then, yeah, that (eagle) was just a great way to finish."

As for Wallace, there were two highlights to his day. A well-struck drive at the short par-4 14th that left him just 6 feet to convert for eagle. Later, he chipped in for birdie from 61 feet out at the par-4 third.

Although he fell out of the top spot, his performance this week has him projected to finish in the Aon Swing 5 to qualify for next week's $20 million signature event, the Wells Fargo Championship. "I'm taking care of my business, what I can do, and putting the best move on it as possible," Wallace said.