FOURTH-ROUND LEADERBOARD (GB & Ireland unless stated):
-15 Z Johnson (US)*, J Driscoll (US) -14 P Goydos (US), B Haas (US) Selected others: -13 J Leonard (US), B Davis -7 G Owen *won play-off
Johnson is the 2007 Masters champion
American Zach Johnson defended his Valero Texas Open crown after defeating James Driscoll in a play-off.
Former major winner Johnson birdied the first play-off hole with a fine 12-foot putt to defeat his compatriot Driscoll who could only par the 18th.
The pair were forced into a play-off having both finished on 15 under par in regulation with Driscoll firing a superb fourth round score of 62.
But it was Johnson, who shot a level 70 on the day, who held his nerve.