If David Lingmerth can finish a major championship as well as he started the last two, there might be a big trophy in his future.

Lingmerth followed his opening 5-under 67 with a 70 to take the clubhouse lead at 7 under halfway through the second round Friday in the PGA Championship.

The Swede pumped his right arm after finishing with a birdie putt on the par-4 18th, which has been the toughest at Whistling Straits. It was a huge confidence boost going into the weekend.

"What was it a 40-footer to finish my day?" Lingmerth asked. "Pretty nice."

He was off by about 5 feet, but it counts just the same.

Last month at St. Andrews, Lingmerth shot a 7-under 29 on the front nine in his opening round to match the record on the Old Course in a British Open. He couldn't keep up that dizzying pace, finishing at even par for 74th place.

"I got a good start at the Open, too ... but very disappointed with how I continued my play that tournament," he said Friday. "To get two solid rounds in the first two here this week, it's a good feeling."

Really, Lingmerth has been playing well since June, when he won he got his first PGA Tour victory at the Memorial after beating Justin Rose in playoff. It gave the 28-year-old valuable experience of playing under pressure.

But that won't compare with the pressure that comes with playing in a late group on a weekend at a major. Lingmerth seems to be taking the attention in stride.

"If I were to have a chance — it's hard to do without having another win behind you," Lingmerth said. "Getting that win improved my confidence going into this week."

Since shaking Jack Nicklaus' hand, Lingmerth had sixth-place finishes at the Greenbrier Classic and Bridgestone Invitational, along with a third-place finish at the Quicken Loans National.

On Friday, Lingmerth played his round in hot, sticky conditions in the morning at Whistling Straits, though the wind had died down considerably from the blustery breezes that whipped off Lake Michigan on Thursday.

"Definitely easier to cope with today ... Now I played in the morning with good greens," he said.

Now if he could just feel better about his long game.

He double bogeyed the par-3 seventh hole after his tee shot landed along the Lake Michigan shoreline. He took a one-stroke penalty drop into the rough, hit his next shot on and needed two putts.

It was the start of a five-hole stretch in the middle of the round that nearly spoiled his morning. Lingmerth had bogeys on Nos. 8 and 9, birdied No. 10 and bogeyed the par-5 11th after hitting his tee shot into a bunker.

His roller-coaster back nine continued with three straight birdies, a bogey on 15 and two pars before the birdie on 18.

Lingmerth was worried enough that he planned to get some extra practice in before the third round.

"I need to go to the range and figure out my ball-striking a little bit better for tomorrow," he said.