(CNN) -- Phil Mickelson produced a eight-under par round of 64 to storm to the top of the leaderboard at the BMW Championship on Saturday.
The American fired 10 birdies and two bogeys in a thrilling third-round display at Crooked Stick Golf Club, Indiana to finish tied with overnight leader Vijay Singh on 16-under par.
"It was a fun day. I got it going with the putter," Mickelson said, PGATour.com reported.
Singh had a mixed round of 69 on Saturday which included seven birdies and four dropped shots.
England's Lee Westwood carded a 68 to leave him in a tie for second on 15-under par along with Northern Ireland's Rory McIlroy who also shot a 68, thanks to a birdie at the 18th.
A tightly-packed leaderboard sees Australia's Adam Scott (66), American's Dustin Johnson (67) and Robert Garrigus (66) a shot further back while Tiger Woods is 13-under par after a completing a one-under par round of 71.
America's Zach Johnson and Bo Van Pelt are on 12-under par along with Northern Ireland's Graeme McDowell.
South Africa's Louis Oosthuizen, who finished runner-up to Rory McIlroy at last weekend's Deutsche Bank Championship, is currently in a tie for 12th on 11-under par along with a clutch of players including England's Ian Poulter and Ireland's Padraig Harrington.