Paired with Tiger Woods, Englishman took advantage of a tie-breaking swing on the 17th hole to take a two-shot lead into the final round at Muirfield.
Lee Westwood has become a major player at this year's British Open
Now the question becomes whether he can finally do likewise against the rest of the British Open field.
Paired with Woods, the former world No 1 took advantage of a tie-breaking swing on the 17th hole on Saturday to take a two-shot lead into the final round at Muirfield, where Woods will have to come from behind for the first time at a major to record a win.
Westwood, alongside Woods for the sixth time in a major championship in the past five years, shot a 1-under 70 and will start the final round two clear of Woods and American Hunter Mahan.
Over those six pairings, Westwood has never been beaten by Woods, claiming the better score four times and tying the 14-time major winner in the other two.
On Sunday, with Westwood in the final group with Mahan, he can concentrate on the bigger task claiming his first grand slam title.
Westwood, 40, has once before held the third-round lead at a major. In 2010, playing partner Phil Mickelson beat him with some eye-popping play at the Masters.
Beginning in 2008, Westwood has amassed seven top-three finishes at the majors, including a runner-up at the British in 2010.
"I know what it takes [to win a tournament]," Westwood said. "It's about believing you're good enough to win. Tomorrow is just another 18 holes. I've just got to go out with composure and try to believe I can win a major tournament."
With an untimely bogey on the 17th, Woods, his playing partner in the third round, might have done serious damage to his hopes of ending a five-year major drought. Woods has won all 14 of his major titles when holding at least a share of the lead after 54 holes. Westwood birdied the hole to get some breathing room heading into Sunday.
"Everybody makes bogeys it's about who makes the fewest," said Westwood, who relocated to the US this year. "The fact I was calm pleased me. My short game was sharp and I made the putts when I needed to."
Woods played solidly for the third day in a row, but blinked on the penultimate hole at Muirfield, which was windier, but not quite as parched, as in the first two rounds.
"It was a grind," said the American star, who will be paired with Adam Scott and Woods' former caddie, Steve Williams, on Sunday. "It was totally different from the last two days, it seemed like they didn't cut some of the greens or didn't roll them, they were much slower. We've had to adjust to different conditions all week and it's hard to get a feel for things.
"I'm a couple back and there's one guy ahead of me and I'll have to play a solid round of golf."
Mahan, 31, who matched the day's low round with a 68, set aside an assertion that he had a chace to make up for losing the key match at the Ryder Cup on British soil three years ago.
"I don't need any redemption or anything like that, just playing golf," said Mahan, the world No 23.
"I'm playing because I really like to play and it's the ultimate challenge playing major golf. So that's the only thing I'm worried about."
Westwood seems to be putting a putting session with former British Open champion Ian Baker-Finch, a neighbour in Florida, to good use. Today will be the ultimate test, of course.
Westwood made an eagle at the fifth hole, and pulled three shots ahead of the field on the front side. Woods fought back and was even with Westwood going to the 17th.
While a partisan crowd surely will be rooting for him, history is not exactly on his side.
Westwood is seeking to become the third Englishman to win the British since 1951, potentially joining Nick Faldo (three times) and Tony Jacklin.
No question, the man nicknamed Westy will be feeling some heat. He might be better prepared this time, making a joke after the day's play.
"Little did I know that when I moved to Florida, I'd be acclimatising for an Open in Scotland," he said of the unseasonably warm week.
Woods lives in Florida, too, and has won a few majors along the way.
"I've got 14 of these and I know what it takes to win it," he said. "[Lee's] won tournaments all over the world. He knows how to win tournaments."
But what about majors? We're about to find out.
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