But while the former world number one struggled to a three-over-par 74, Westwood compiled a six-under 65 that was matched minutes later by American Kevin Chappell.

Westwood, who carded a closing 63 at Firestone Country Club on Sunday after missing the cut in his previous four events, looked to have squandered a good start when he covered the back nine in 33 only to run up a double bogey on the first.

However, the 41-year-old bounced back with a birdie on the fourth and rattled in four more in succession from the sixth, ending his round in style by holing from 40 feet on the ninth.

Italian Edoardo Molinari was five under par with four holes remaining, while Holland’s Joost Luiten and England’s Ian Poulter boosted their Ryder Cup chances with rounds of 68 and Colin Montgomerie returned a highly respectable 70.

“I wanted to represent the Champions Tour well and 70 is okay to start with,” said Montgomerie, who qualified by winning the Senior PGA Championship in May. “I drove the ball well and knew if I did that I could get round.”

World number six Matt Kuchar could not say the same thing, the American withdrawing before the start of play with a back injury as the problems mounted for US Ryder Cup captain Tom Watson.

Dustin Johnson has already made himself unavailable for the team due to “personal challenges” while defending US PGA champion Jason Dufner is struggling with two bulging discs in his neck.

Kuchar, who has already sealed his place on the Ryder Cup team for Gleneagles, was replaced in the draw by first reserve John Huh.