Charlie Wi began the third round at Colonial Country Club just hoping to cut into playing partner David Toms' big lead. Wi certainly never expected to be leading at the end of the day.

Toms blew a seven-stroke margin Saturday, and Wi took the lead with a 32-foot birdie putt on the par-3 16th hole. At 13 under after a 4-under 66, Wi had a one-stroke stroke edge over Toms — and the 54-hole lead on the US Tour for the first time in his career. A victory would move Wi from 104th into the top 25 in the FedEx Cup standings.

"I'm very pleasantly surprised. I played really well today and David didn't," Wi said. "It's such a crazy game. I don't know what to say."

Soon after weather delay of 1 hour, 20 minutes, Wi's tee shot at No. 16 landed on the back side of the green and Toms pushed his shot right into the rough. Wi holed the birdie putt before Toms' 16-foot par chance just missed for a two-stroke swing that changed the top of the leaderboard.

"Tough day overall," said Toms, who shot 74 after building his huge lead with bogey-free 62s.

Toms opened with a birdie Saturday, but had three bogeys in a five-hole stretch while Wi got started with consecutive birdies.

Even worse for Toms was a three-putt from 7 feet for double bogey at No. 14, where Wi chipped to 12 feet to save par before the delay.

"Until then I was still three behind him, so I wasn't even thinking about the lead or anything," Wi said. "Then it's `Wow, I'm only one shot behind him.' I knew it was getting a lot more interesting than how I envisioned when I started the day."

Wi made his 100th cut in 147 US Tour events this weekend, but the 39-year-old South Korean has never won.

The 44-year-old Toms is a 12-time winner, but is looking for his first victory in more than five years. He is coming off a playoff loss to K.J. Choi last weekend at the Players Championship.

While Toms now has another disappointment to overcome, at least he still has one more round to play at Hogan's Alley.

"I'm right where I set out to be when I started this week," Toms said. "I certainly would like to be sitting here with a 10-stroke lead and trying to break some record or something like that. It's all about getting in position and see how I do. I did well last Sunday with a chance, but didn't quite get there."