Hunter has Haas in his sights
Bill Haas was battling to retain his Northern Trust Open title after seeing his lead whittled to one by the midway point of his final round.
Haas had boasted a three-shot advantage heading into the last day following his brilliant seven-under-par 64 on Saturday but the American was struggling to replicate that form on Sunday.
The defending champion started promisingly with a birdie-bogey-birdie start but further dropped shots on the seventh and eighth saw Haas reach the turn one over for the round.
That also saw him slip back to 11 under for the tournament, and allowed four players to close to within one shot.
Leading the charge was Hunter Mahan, who was four under after 10 having recorded five birdies and a bogey on his front nine.
Also in contention on 10 under were two other Americans, John Merrick and Webb Simpson, who were both one under after nine, and Swede Fredrik Jacobson, who was two under midway through his final round.
Charl Schwartzel, who along with Merrick and Simpson was in joint second place overnight, was on nine under along with Charlie Beljan.
England's Luke Donald remained eight under for the tournament after reaching the turn in even par today, picking up shots on the first and ninth but bogeying the third and sixth.