By Jean-Paul Salamanca (staff@latinospost.com) | First Posted: May 30, 2013 09:26 PM EDT

After the first day of the PGA Memorial Golf Tournament, Tiger Woods found himself six strokes behind Charl Schwartzel, who is on top of the leaderboard standings at the tourney.

Woods, who won last year's tournament, hit five birdies but was thrown off by four bogeys during the first day of the action at Muirfield in Dublin, Ohio, hitting only for 1-under 71 and outplayed by Fred Couples, a winner at the Memorial in 2006, who put up a mark of 70 with only 25 putts.

"I didn't score very well compared to how I hit it,'' said Woods. "I hit it pretty good. I just didn't make anything today.''

The No.1-world-ranked player in golf, Woods had entered the tournament having won four of the last five tourneys he had played, including the Players Championship, as he looks to build momentum for the upcoming U.S. Open in June.

Schwartzel, a former Masters champion, had a strong day with four straight birdies at one point and netted another one to shoot for a 7-under-65 for the opening round, putting him with a one-shot lead over Scott Piercy.

Rory McIlroy, the No.2-ranked player in the world, hit for 78, including a four-putt double bogey at the 12th hole, and expressed his frustration afterwards. McIlroy's 78 marks the highest first-round score of his career, according to ESPN.

"I'm fully focused on what I need to do," McIlroy said, as reported by ESPN. "And I didn't think I played as bad as the score would say ... I thought coming off the back end of last year, winning the PGA Championship, I wanted to do the same sort of things. It just hasn't happened. I haven't lived up to my own expectations."

McIlroy finds himself in a bit of a slump heading into Thursday in Ohio. He tied for 25 at the Masters and ended up tied for 10 place at the Wells Fargo Championship and tied for eighth at the Players Championship, though he was knocked out of contention in the last nine holes for that tourney.