Carl Pettersson leads @ RBC Heritage at Harbour Town April 15 2012

 Carl Pettersson Hits                                                                                                                    Getty Images Carl Pettersson leads the RBC Heritage at Harbour Town by one shots from Colt Knost. Carl had a -5 under par third round 66, for a tournament total of -12. Colt could only manage a round of -2 under par for a total of 69 and -11 under par tournament total. Carl and Colt  chatted and laughed throughout the round, and appeared oblivious to the fact that both golfers were chasing a PGA TOUR title. Carl beamed in interview; "Two fat guys played in three hours, 48 minutes. That was pretty good. But we had a good time.  I played great all day. I obviously started off really well with five in a row. And I kept going. Made a nice birdie on 10. Made a weak bogey on 11. I was just left of the fairway, but it wasn't that hard of a shot, it hit the green. But I was fine with making five after the second shot. And I put myself in an awkward spot. But bogey on 15 was a little frustrating. But kind of got me fired up to play well coming in. And I managed to birdie the 18th, which was nice. Colt Knost, who is chasing his first PGA Tour win, said it was his intention to have fun while still competing, he will partner Carl again tomorrow in the final pairing. "I'm going to try tomorrow to have fun," he said. Lets hope he has a better start than the bogey he had on #1 today; "I could have got rattled pretty easy after that start, but like I said, I'm really proud of the way I hung in."

 Colt Knost SmilesGetty Images

Zach Johnston shot a -5 under par round of 66 to move into third place at -8 under, four shots behind the leader, Carl Pettersson. He was still hopeful of mounting a serious challenge tomorrow, he said; "We've still got 18 holes, the last four or five holes, if I'm near the lead, we can get after it a little bit. I think there was a five to ten percent chance of rain today, but we got it. It didn't really matter, it didn't soften it up, and didn't cause any effect on any shots. It was a good day. I got off to kind of a slow start and managed to right the ship. And made some nice, key putts." World number one Luke Donald could only manage a par round of 71 and remains at +2 for the tournament. He will  he will fall from World No. 1 after he finishes Sunday, surrendering the top spot to Rory McIlroy. It has been another sad tournament for Luke and he needs to right the ship pretty quickly. Luke Donald, Of England, Hits