Phil Mickelson was delighted with Sunday's timely 62 that has helped him build confidence on the eve of the USPGA Championship at Valhalla this week.

The American, the 2005 USPGA Champion, finished the WGC-Bridgestone Invitational with the best round of his season and now feels that everything is coming together ahead of the final Major of the year.

"In this game, things can turn around really in an instant," Mickelson told reporters on Tuesday. "I don't want to put too much into one round. I'm interested to see how it goes Thursday and Friday, but certainly my confidence level and my practice sessions are totally different.

"I don't feel like I'm searching. I feel like I'm just trying to now acquire that same feel from Sunday and I feel like I've found what I'm looking for. I just have to maintain it. Sunday was a big day for me because it just kind of fell together. I felt like the pieces were close, I played some good golf and it felt like it started to fall together.

"I've been waiting for it to just click and all come together in a round and I felt like once that happened there would be some momentum. It's a really good thing for me to get that kind of momentum from one round. The way the pieces fell together, I started to roll the ball well and wedge play started to get good, short irons got better and just really two days prior, it was just horrific. So it was an important day."

Mickelson came from the back of the field to finish 15th at Firestone, where Rory McIlroy was victorious.