Lawrie had already been in the clubhouse for hours by the time Willett finished his round, securing a tie for second place after 18 holes at St Andrews after the winds began to increase.
Conditions were still fairly reasonable when Willett began his round, and he took fully advantage with birdies at the first three holes.
He moved to five under with an eagle at the par-four 10th, gave a shot back at the next but managed two more birdies on the way home, capping his round by canning a putt at the last to move to six under.
“Since the US Open and French Open, I have played good golf,” he said.
“It’s the more you play with the guys, the more you realise that they don’t do??things a great deal better than you, if not at all.
“The more and more you’re in and around this atmosphere and in and around this??kind of golf, the more you realise ‘Actually, yeah, I’m pretty equipped to do??pretty well out here’.”
Lawrie, champion in 1999 at Carnoustie, was in inspired form during the morning session, his putter in red-hot form as he birdied seven of the first 13 holes to briefly take the outright lead.
A dropped shot at the 17th was the only blot on his card, but the Scotsman was delighted to start in such positive fashion, especially with the weather forecast to deteriorate on Friday.
“Obviously it was quite calmish this morning, so it’s important to take??advantage of those conditions if you can,” he said. “I have actually won tournaments in nice weather, not just bad weather, so it??doesn’t matter what comes. I don’t wish for it.”
Three more Englishmen made the most of their early draw to post four-under rounds of 68, among them Luke Donald who continues to round into the form that took him to world No 1.
Donald had four birdies on his front nine and parred all the way in for a bogey-free 68, the same score as compatriots Greg Owen and David Howell and Scotland’s Marc Warren, who almost holed for a birdie from the Road Hole bunker.
“I had a few chances coming in but also had a couple of good saves. I made a good save on 13, 14 and 17, so bogey-free is always a nice way to start.” Donald said.
“I felt good about my preparation and I felt good about the way I have been playing, so there was no reason not to go out there and shoot a good round.”
Also making a positive start, among those with a later tee-time, was Southport-born Tommy Fleetwood, a player with plenty of links experience.
Fleetwood had five birdies and two bogeys in a round of 69, while Anthony Wall and Tyrell Hatton finished in red figures with two under 70s.
The news was not quite so positive for Justin Rose, who looked to be in position for a challenge at Dustin Johnson’s lead when he reached the turn in four-under.
But he carded four fives in his last six holes to give three of those shots back, finishing with a sloppy three-putt bogey at the 18th.
The opening round was also a struggle for Ian Poulter, who continues to search for a first major title. Poulter was unable to get his putter going, making only one birdie and two bogeys in a disappointing 73, the same score as Ryder Cup team-mate Stephen Gallacher.