Hilton Head Island, SC (SportsNetwork.com) - Graeme McDowell and Matt Every posted matching 5-under 66s on Thursday and share the lead after the opening round of the Heritage.

McDowell, the 2013 champion, has made three cuts in his last six worldwide starts and his best finish was a share of 36th in Malaysia. Every's only top-25 finish this season came at Bay Hill, where he won his second straight Arnold Palmer Invitational title.

Sang-Moon Bae opened with a 4-under 67 at Harbour Town Golf Links and is alone in third place. Defending champion Matt Kuchar carded a 3-under 68. He was joined in fourth place by Kevin Kisner, Morgan Hoffmann, Scott Langley and Cameron Smith.

Johnson Wagner, who lost in a playoff at the Houston Open, shot 2-under 69. Among the 12 players he shares ninth place with were Pat Perez, Ian Poulter and former Open Champion Louis Oosthuizen.

Masters winner Jordan Spieth struggled throughout the day and posted a 3-over 75, which left him tied for 93rd place. Spieth carded a double-bogey, two bogeys and a birdie in his round.

"I didn't drive the ball well, I didn't particularly strike my irons well, and chipping and putting wasn't there. Just was an off day," Spieth admitted.

McDowell stumbled to a bogey on the first, but that was his only dropped shot of the day. His third shot to the par-5 second stopped 32 feet from the hole, but he poured that in for birdie.

The Ulsterman birdied the next par-5, the fifth, and two holes later, dropped in a 9-foot birdie putt at the seventh. He parred the final two holes of the front nine.

McDowell quickly moved atop the leaderboard early on the back nine. He rolled in a 16-foot birdie chance at the 10th. After a par on 11, McDowell moved into the lead thanks to back-to-back birdies at 12 and 13. He parred the last five holes to share the lead.

"I drove it in the fairway, which I haven't been doing enough of this year, and I just felt really good on the greens," said McDowell. "You have to stay patient (on this course). You have to position the ball well at all times, and you have to really be aware of the wind on this golf course."

Every played the back nine first and opened with three pars in a row. He got on the board with a 5-foot birdie putt at the 12th, then followed that with three more pars.

The two-time Arnold Palmer Invitational winner birdied the 17th from seven feet out, but gave that shot right back as he bogeyed the difficult 18th.

Every got up and down for birdie from a greenside bunker at the second, then birdied the fourth to climb to minus-3. He holed a long birdie effort from off the green at six, then chipped in for birdie on seven to join McDowell in the lead. Every parred the last two holes to end there.

"I just got a ton out of it," Every said of his round. "I chipped in twice. It's a weird game. That's probably the worst I hit it in a while. Last week, I felt like I hit it great and I missed the cut, and today was the complete opposite. Weird game, but I'll take it."

NOTES: McDowell and Kuchar are among the former winners in the field trying to become the 10th player to win the Heritage more than once ... Spieth's streak of 17 consecutive rounds at par or better came to an end ... Jim Furyk, the 2010 champion, carded 18 pars and was the only player that was bogey-free in the opening round ... Andrew Svoboda had a hole-in-one on the par-3 seventh for the 21st ace on the PGA Tour this season.