Keegan Bradley had been in second place, but a bogey at nine had dropped him to two shots back. However, an eagle on the 12th hole ties him with Jason Dufner, who added another birdie at the eight to move up to -9, and stays ahead in first by one shot after 11 holes.
Robert Karlsson from Sweden is making the biggest possible surge at the best possible time. Karlsson has kept his fourth round scorecard spot-free with no bogeys through the first thirteen holes. He was -3 through the front nine, birdied the tenth, then moved right into second place when he eagled the 12th. He is now six-under through his round and at -8 for the tournament through 13 holes. Unfortunately, it's still not enough to put him ahead of Dufner.
Anders Hansen from Denmark has moved up to -7 and David Toms & Scott Verplank has also made a late charge to get to -6. With not many holes remaining, these look like your main contenders for the PGA Championship title.