HOUSTON (Reuters) - Former Masters champion Zach Johnson birdied the last hole to complete a final round of 64 and win the Texas Open by two strokes on Sunday.

Johnson, the 2007 Masters winner, finished on 19-under 261 to claim his fourth PGA Tour victory and first of the year ahead of South Korean Charlie Wi, American Mark Wilson and New Zealander Tim Wilkinson.

Wi shot a nine-under 61, Wilson 63 and Wilkinson 64 to finish in a three-way tie for second place on 263.

Johnson made seven birdies and only one bogey, at the par-four second hole, at the La Cantera Golf Club's Resort Course in San Antonio.

Overnight leader Rory Sabbatini struggled on the final day and finished tied for eighth, the South African producing a double bogey on the first hole and another at the 15th on the way to a round of 72.

(Writing by Gene Cherry in Raleigh, North Carolina; Editing by Ed Osmond))