Phil Mickelson arrived here with 17 previous British Open appearances, one top-10 finish and, by his telling, a completely different attitude about this event.

“I just wanted to start fresh, because I’ve loved links golf,” Mickelson said. “I just had to really enjoy the challenge of it more.”

Through two rounds at Royal St. George’s, he is enjoying it as well as at any point in recent memory. Mickelson shot a relatively clean 1-under-par 69 Friday to finish at 1-under 139 at the midway point of the British Open, just three shots behind the pace set by Darren Clarke and Lucas Glover.

“It’s fun to be in contention at any major,” Mickelson said. “But it’s fun for me to be in contention at the Open Champiponship because I haven’t been here that often. . . . This is a really fun tournament, so to have a chance to be right in it, it’s exciting.”

The only time Mickelson contended at the British Open was 2004, when he finished third at Royal Troon, one shot out of a playoff with Ernie Els and Todd Hamilton, who won. Just two other times has he finished in the top 20.

SANDWICH, ENGLAND - JULY 15: Tom Watson of the United States takes a bow after his hole in one at the sixth hole. (Stuart Franklin/GETTY IMAGES)

Since winning the Masters in 2010, Mickelson has struggled, winning just one other tournament. His finishes in the last four majors: tied for 48th, tied for 12th, tied for 27th and tied for 54th in the U.S. Open last month at Congressional.

“The last two years have not been what I wanted,” Mickelson said. “But I can feel things are starting to turn a little bit.”

Aces, dear Watson

Tom Watson is 28 years removed from the last of his five British Open titles and two years removed from his stirring run to the lead in this tournament at Turnberry, only to bogey the 72nd hole and lose in a playoff to Stewart Cink. Friday, in his 34th Open appearance, he thrilled the galleries here with a hole-in-one at the sixth, a 4-iron that hopped once and shot into the hole.

“It was into the wind about 160 yards,” Watson said. “Old guys hit 4-irons 160 yards into the wind. The kids are hitting 6-irons.”

Watson, 61, said he has 15 aces in his career, most of them in competitive rounds, but only one other had come in major championship play: In 1980, an ace at Baltusrol’s fourth hole in the first round of the U.S. Open.

Dustin Johnson aced the 16th hole Thursday.

Heading home

Graeme McDowell won the 2010 U.S. Open and won the clinching point in Europe’s victory in the Ryder Cup, part of a breakthrough year. But after following his opening 68 with a mystifying 77 Friday, McDowell has missed the cut in three of his last four majors: the PGA Championship last year, the Masters and British Open this year.

“I’m just not in the right frame of mind right now,” he said. “. . . There’s something going on. Maybe my expectation level is putting a little too much pressure on myself.” . . .

University of Virginia grad Steve Marino shot a second-round 76 to finish at 10 over for two rounds, missing the cut, the first time he has failed to play the weekend in three British Open appearances.