* Barnes shoots 67 to take outright lead * Seeks first PGA Tour win in 222nd start * Steele alone in second after carding 72 (Adds detail, quotes) April 23 (Reuters) - American Ricky Barnes, a former U.S. amateur champion seeking his first PGA Tour victory, birdied four of the last eight holes to grab a one-shot lead after the third round of the Texas Open in San Antonio on Saturday. Playing his eighth full-time season on the PGA Tour, Barnes posted an 11-under total of 205 to end the round a stroke in front of his compatriot Brendan Steele, the 36-hole leader who slipped off the pace as he ground out a 72. American Charley Hoffman, bidding for his fourth win on the U.S. circuit, carded an adventurous 70 on a sun-splashed afternoon to finish at nine-under, level with England's Luke Donald (68). More...