Donaldson, a 35-year-old Welshman seeking his first career victory, was at 14 under and one shot ahead of Westwood. McIlroy was another stroke back in third on a sun-baked day in the Alps.
“I’m the underdog, in effect, even though I’m winning by one,” Donaldson said, referring to Sunday’s final group. “It’s awesome. You are playing with two of the greatest players at the moment.”
Westwood, ranked No. 2, had seven birdies, including all four par-5s, in a 64 that was the day’s best round.
“It’s always nice to play a round with no 5s and no bogeys, especially on a course like this that can trip you up,” Westwood said.
McIlroy began the day in a four-way tie for the lead at 8 under, but the US Open winner dropped shots at the 16th and 17th in his 67.
“It wasn’t the greatest way to finish, but I’m still in there,” he said.
Thomas Bjorn of Denmark, last week’s winner at Gleneagles, Scotland, had a 66 and was at 11 under with Gary Boyd of England. Martin Kaymer of Germany was among six players at 10 under, trailing Donaldson by four shots.
Donaldson shot seven birdies, the lone bogey coming at the 629-yard ninth hole.
“I played really good all the way round,” said Donaldson, who has two runner-up finishes on the European Tour, most recently at Malmo, Sweden in July 2009. “I will go out (Sunday) with the exact same game plan.”
Westwood’s round included four straight birdies between the sixth and ninth holes.
McIlroy birdied the first and sixth then sank a 40-feet putt for an eagle-2 at the scenic seventh hole. He got back-to-back birdie-4s after the turn before his putting let him down at the par-3 16th.
Matteson sets pace, Donald one behind
In Norton, Massachusetts, British world No. 1 Luke Donald signalled an ominous warning to his FedExCup playoff rivals by firing a 5-under 66 in Friday’s opening round of the Deutsche Bank Championship.
The Englishman mixed six birdies with a lone bogey to lurk just one stroke off the pace set by American Troy Matteson at the TPC Boston.
“It was a good round,” Donald told reporters. “I feel like I’ve been hitting the ball pretty well the last few days. I did miss a couple (of putts) coming in but I made a good few out there and was very happy with the score.”
Entering this week’s event, the second of the PGA Tour’s four lucrative playoff events, Donald occupies fifth spot in the overall standings and trails FedExCup leader Dustin Johnson by 1,583 points.
The long-hitting Johnson also made a good start on Friday and was among a large group including PGA Championship winner Keegan Bradley, former Masters champion Zach Johnson and Rickie Fowler after carding a three-under 68.
Matteson, a double winner on the PGA Tour, opened his round with a bogey at the 10th but rebounded with seven birdies the rest of the way to take control at the top.
He began this week a precarious 97th in the FedExCup standings and well aware he needs to sparkle at the TPC Boston if he is to advance.
The leading 70 players after the Deutsche Bank Championship move on to the BMW Championship at Cog Hill before the top 30 qualify for the Tour Championship finale at East Lake.
Donald got off to a fast start with a birdie at the first but dropped a shot at the second before immediately responding with consecutive birdies.
Further birdies at the seventh, 10th and 11th put him at five under and seemingly on track to claim the outright lead but he parred his way home to stay one shot off the pace.
Masters champion Charl Schwartzel of South Africa, 2009 PGA champion Yang Yong-eun of South Korea and American Jerry Kelly ended the round level with Donald after carding matching 66s.
Four-times major winner Phil Mickelson returned a 70 after putting a belly putter in tournament play for the first time. Notably Mickelson did not three-putt once during his round.
