While Tiger Woods mainly struggled in his first competitive round in three months, Australian Greg Chalmers birdied his last three holes to seize control of the Quicken Loans National in Bethesda, Maryland.
Chalmers, at the age of 40 still seeking his first victory on the PGA Tour, fired a five-under-par 66 on a difficult Congressional Country Club layout bristling with thick rough to take a one-shot lead in the opening round.
The Australian left-hander picked up three shots in his first nine holes after teeing off at the par-three 10th, then bogeyed the second before ending his round in style with birdies at the seventh, eighth and ninth.
That left Chalmers a stroke in front of long-hitting American Ricky Barnes and Swede Fredrik Jacobson, who carded matching 67s.
"I really drove the ball well, probably the best I have driven it all year," Chalmers told PGA Tour Radio. "That kind of set up the rest of the round, and finishing with three straight birdies is always nice."
Woods, playing in a high-profile grouping with compatriot Jordan Spieth and Australian Jason Day, initially looked rusty and struggled with seven bogeys in his first 12 holes before recording three birdies in his last six to shoot a 74.
"I made so many little mistakes," Woods, who had surgery to repair a pinched nerve in his back in March, told reporters after finishing the round tied for 83rd in a field of 120. "But I played a lot better than the score indicated, which is good.