Rory McIlroy vowed to “keep the pedal down” as he looked to turn a narrow halfway lead into a second major title in four weeks in the 96th US PGA Championship.
McIlroy, who is looking to become the first winner of back-to-back majors since Padraig Harrington in 2008, won his first two major titles by eight shots and led from start to finish to claim the Open Championship at Royal Liverpool last month.
But the world number one still has painful memories from letting slip a four-shot lead in the Masters in 2011, when he collapsed to a closing round of 80 at Augusta National.
“I think I’ve had to learn to be a good front-runner,” the 25-year-old said. “I maybe wasn’t quite comfortable in that position at the start of my career, especially 2011 in the Masters.
“It’s taken me a couple of years to grow into that and my mindset has stayed the same since that day at Augusta. If I’m two ahead going into the weekend here, I’m going to try to get three ahead, and if I’m three ahead, I’m going to try to get four ahead.
“I’m just going to try to keep the pedal down and get as many ahead as possible. I went into protection mode once in my career and that did not work out very well so I said would never do it again.”
McIlroy was two ahead for much of the day after adding a 67 to his opening 66 - matching the rounds shot by Tiger Woods on his way to victory here in 2000 - only for Australian Jason Day and American Jim Furyk to close within a shot late in a rain-affected second day.
Finland’s Mikko Ilonen and American duo Rickie Fowler and Ryan Palmer were a shot further back on seven under, with Phil Mickelson and Austria’s Bernd Wiesberger on six under. First round joint-leader Lee Westwood is four off the pace after a 72.
Fowler has already finished in ties for fifth, second and second in the year’s previous three majors and the 25-year-old would love another battle with McIlroy this weekend.
“I’d say each major I’ve felt more and more comfortable,” Fowler said. “The Masters is the most comfortable I had felt in a major and then being in the final group at the US Open and another final group with Rory at the Open, I felt more comfortable there than I did with Martin (Kaymer at Pinehurst).
“It doesn’t feel like a big stage. I feel like I’m out there having fun. I like where my game is at. It will be a battle this weekend and I’m looking forward to it.
“Rory is obviously on top of his game right now. He’s been driving the ball very well. When he does that, it kind of alleviates any stress from anywhere else and he’s able to go full throttle and not really let up.
“The Open definitely wasn’t the last final group of a major that him and I will be a part of. Maybe we’ll get another one for Sunday.”