Zach Johnson shot a third-round 60 but still needed a play-off to successfully defend his title at the Valero Texas Open. A day after the 2007 Masters champion had equalled the course record at the par-70, 6,896-yard Resort Course with an eight-birdie, one-eagle round of 60, fellow American James Driscoll shook things up with an eight-under-par round of 62 to take the clubhouse lead at 15-under. Johnson, who had held the 54-hole lead by two strokes from Paul Goydos, failed to continue the momentum he had enjoyed the previous evening, his closing round of 70 sending him into sudden death with Driscoll. The defending champion had won his only previous play-off, at the 2007 AT&T Classic, while Driscoll had lost his, at the 2004 Zurich Classic and Johnson put himself in perfect position for a second such win with an approach shot to 10 feet. Driscoll had a chance to reflect the pressure back on his rival from 29 feet but his putt broke right, leaving Johnson to successfully putt out for birdie and the seventh PGA Tour victory of his career. Johnson had completed his round on Saturday night at the end of a day when threats of lightning and thunderstorms in San Antonio brought play to a halt for almost five hours. His 60 gave him the clubhouse lead, the final putt rolling in as the hooter sounded to call play to a halt due to fading light, leaving his rivals to return on Sunday morning to complete their third-round play. With all those rounds in the books, Johnson was the 54-hole leader at 15-under, two strokes clear of halfway leader Paul Goydos with Justin Leonard another shot back at 12-under-par. Playing in three-man groups from both tees to make up the lost time from Saturday, Johnson teed off for his final round with Goydos and Leonard but was not able to continue the momentum of the previous evening. Level par for the day on his front nine, he bogeyed the par-four 10th to fall to 14 under, alongside Goydos, one under for the day. Driscoll had joined Johnson in the lead with one hole left to play, seven-under for the day after five birdies and an eagle at the par-five 14th and he moved into the lead with a 15-foot birdie putt at the last. Johnson got back to 15-under and a share of the lead with Driscoll after holing out from 13 feet from the fringe of the green but Goydos&apos round suddenly came to life on the closing holes with birdies at the 14th and 16th to move into the outright lead at 16-under. Just as the lead came to him, Goydos threw it away, bogeying the 17th and 18th to finish at 14-under and in a tie for third alongside Bill Haas who had produced a final-round 65. Leonard, the first round co-leader with Goydos, closed with a 69, in a tie for fifth place at 13-under alongside England&aposs Brian Davis. Davis had birdied the ninth, his 72nd hole, for a 66, his second consecutive top-10 finish following his tie for fifth at last week&aposs Players Championship. Also finishing on 13-under was Australian Marc Leishman and Sweden&aposs Fredrik Jacobson, who birdied the last for a closing 67. James Nitties completed a consistent tournament in a share of 17th place at nine-under after a closing 68, while Matt Jones stormed home with a five-under 67 to finish at seven-under overall. Meanwhile, a star was born on Sunday when local hero Shane Lowry became just the third amateur to win on the European Tour – at the Irish Open on the third extra hole. But what agonies the 22-year-old had to go through at County Louth before he got the better of England&aposs Robert Rock in their sudden death play-off. Son of a famous Gaelic footballer, Lowry was poised for glory when he pitched to within four feet of the final flag. But, having raised his cap to the ecstatic crowd as he walked onto the green, he was covering his face in it when he pulled the putt wide. Rock missed a nine-footer at the first play-off hole and after the next was shared in birdies Lowry&aposs tap-in putt for a par five next time round – their fourth playing of the long 18th in the day – gave him the trophy as Rock had pitched over the green and by failing to get up and down ran up a six. Third was Swede Johan Edfors, while joint fourth were England&aposs Nick Dougherty and Scot Marc Warren. Australian Brett Rumford finished in a tie for eighth at nine-under while Marcus Fraser shared 41st at one-under.