For a second straight day, Kevin Na recorded the lowest score at the Colonial, notching a 4-under 66 to drop to 10-under for the tournament and open up a 2-stroke lead.
Na could have made it a 3-stroke lead but he bogeyed No. 18 after racking up five birdies between No. 10 and No. 17.
He has a two-stroke lead over the UK’s Ian Poulter, who appears to be making the right choice by forgoing the BMW PGA Championship this week. Poulter fired a 67 on Friday after his opening round 65 on Thursday.
The Ferrari-loving Brit had a fairly erratic round, 4-under through eight holes, but then struck three bogeys between No. 9 and No. 16.
Boo Weekley, who started the day tied for first, fell back to third, three strokes off the pace, with a 1-under 69 to stand at 7-under.
The most unexpected slide of the day came from world No. 2 Jordan Spieth, who staggered to a 3-over 73 to fall to a tie for 15th. Spieth started off with a birdie, but fell into a big hole shortly thereafter when he bogeyed No. 4 then triple-bogeyed No. 5 with a 7. Another bogey on No.8 saw him 4-over at the turn. He salvaged a birdie on No. 14 to earn one stroke back.
One of the best surprises of Friday came in the form of Vijay Singh, who shot a 4-under 66 to rise from 40th into a tie for sixth through 36 holes. This is just the second PGA event of the year for Singh, who had five birdies and one bogey on the round.
Singh has not won a PGA event since 2008.