HILTON HEAD ISLAND, S.C. — Save the fitness trailer for the rest of the PGA Tour, Carl Petterson knows he’s fine the way he is.

Petterson used another fast start for a 2-under 69 and a five-shot victory over Zach Johnson on Sunday at the RBC Heritage. Pettersson has never fit the tapered, powerful build made popular by Tiger Woods and copied by scores of young players.

The one time the 34-year-old Pettersson did slim down and lost 30 pounds, he also lost his winning golf swing.

“Ultimately, just cause you don’t look like an athlete doesn’t mean you’re not an athlete,” Pettersson said. “We’re not running a marathon out here, we’re walking 18 holes.”

And no one walked them better this week at Harbour Town Golf Links than Pettersson. He finished at 14 under to win his fifth PGA Tour title and first since 2010. Pettersson also tied countryman Jesper Parnevik for most ever on tour by a Swedish player.

“It was great,” said Pettersson, now a U.S. citizen. “I didn’t want to put too much pressure on myself, so I kind of downplayed the whole thing. But getting off to a birdie on one was great.”

Pettersson, second in the Houston Open two weeks ago, earned $1,026,000.

Top-ranked Luke Donald needed to finish eighth or better to retain his ranking, but tied for 37th and will fall behind Rory McIlroy.

Johnson shot a 70 to finish second at 9 under, while Colt Knost’s chances for his first PGA Tour title fell apart with a 74. He was third at 8 under.

Kevin Stadler (68) and Billy Mayfair (69) tied for fourth at 6 under. Two-time Heritage winner Boo Weekley had his worst round of the week, 73, to tie for sixth with Matt Bettencourt (69).

Masters winner Bubba Watson and most of the world’s best took the week off to recover from the year’s first major.

No one, though, was catching Pettersson in this one. He rolled in a 24-footer on No. 1 to get things started with a birdie. He added another birdie, from 16 feet on the par-3 fourth hole, then two-putted from 40 feet on the par-5 fifth to go up by four shots. When Johnson took bogey at No. 10, Pettersson was five strokes in front and cruising.

Pettersson used a run of five straight birdies on the front side Saturday to gain the lead. He was 13 under on the front nine the four days.

“I like all the holes,” he said. “I don’t have one hole on the front nine where I feel awkward over the tee shot or second shot.”

He also didn’t feel too bad on the greens, needing just 104 putts over 72 holes.

Knost was on top after Thursday and Friday and felt good as part of the final pairing. But those nerves Knost acknowledged Saturday were apparently back again in the final round.

He missed an 8-foot putt for par and made bogey on No. 1 for a second straight round to drop three shots behind Pettersson. And just like Saturday, Knost fought back with a birdie on the second hole — he made eagle there in the third round — to close in on Pettersson.

However, Knost’s chances ended a hole later with a horrible drive out of bounds left on No. 3 that led to a triple-bogey seven and left him five shots behind and out of contention.

When Knost flew his approach to the 12th green way left, he simply stood in the fairway and stared straight ahead, hands on hips, in disbelief.

“I hit it good this weekend, but the one swing (on No. 3) got me in trouble,” Knost said. “I made 7 and that was kind of it.”

In other events on Sunday:

Allen gets second Champions title

LUTZ, Fla. — Michael Allen won the Encompass Insurance Pro-Am for his second Champions Tour title, closing with a 3-under 68 for a three-stroke victory over Kenny Perry. Allen finished the three-day event at 12 under. He took a five-shot advantage into the final round, tying the tournament record for the largest 36-hole margin.

Oosthuizen takes Malaysian Open

KUALA LUMPUR, Malaysia — Louis Oosthuizen won the Malaysian Open, a week after losing a playoff to Bubba Watson in the Masters. The South African completed a 3-under 69 in the rain-delayed third round, then closed with a 68 for a three-stroke victory over Scotland’s Stephen Gallacher. The 2010 British Open champion finished at 17-under 271 on Kuala Lumpur Golf and Country Club’s West Course.