England's Lee Westwood remains hopeful of winning the Masters despite heading into the final round five shots behind leader Peter Hanson.
Westwood, the world number three, struggled with his game on day three and carded a level-par 72.
He said: "I wasn't striking it properly. I hit it short, so that makes this golf course tough. It was a good scramble to get around in 72.
"I'm only five back. It's not as close as I'd like, but there's a chance."
Westwood, who is still searching for his first win in a major, added: "Charl [Schwartzel] made all those birdies to finish last year. Anything is possible.
"This golf course gives you a chance if you're playing well. They've got the flags set so you can make a couple of eagles."
set his sights on winning a fourth major after shooting a third-round 68.
The Irishman, who won the Open in 2007 and 2008 as well as the US PGA in 2008, birdied five of his last six holes to move to four under, five off the lead.
Garcia and McIlroy embrace
"I definitely think there's cycles in this game," said Harrington.
"When I look at major winners over time, certainly multiple winners, they never all won them together; it took them 10, 15, 20 years to win them."
followed two level-par rounds with a two-under 70, including six birdies and four bogeys.
"It's a good score," he said. "To say it was a mixed bag - it was very close to being a very low round of golf.
"The front nine was a rollercoaster ride and having six birdies and only shooting two under was frustrating, but hopefully by the back nine [on Sunday] I'll be in a good position.
"We all know what they do with the pin positions on a Sunday and it does open up the golf course to low scoring. I'll have to make birdies when I can."
was four under for his round and the tournament through 14 holes, but, after finding water on the 15th, he dropped four shots over the final four holes.
"I played well for the first 14 holes," said the world number nine.
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“We couldn't really feed off each other's good energy because there pretty much wasn't any. Our bad holes were really bad and our good holes were bad ”
"It was nice to get to four under with a nice run of birdies on the front nine and get momentum going but disaster struck on last four holes.
"[On the 15th], I thought it was plenty of club. It looked good and landed on the green but as I started walking the ball ran back down into the lake. From then on it's a tough finish."
After a third-round 77, world number two
said he needed the hug he got from playing partner
on the 12th green.
"I think we were both needing it," said McIlroy, who went out in 42. "We didn't have our best stuff with us. If you can't laugh at yourself who can you laugh at?"
Garcia, who carded a 75, said: "We couldn't really feed off each other's good energy because there pretty much wasn't any. Our bad holes were really bad and our good holes were bad."
, who goes into final day five off the lead after a 70, said he was not worried about the wheels falling off, because they have fallen off "so many times already".
"It's just fun to go out and try and make birdies and save myself from impossible situations," said the Swede. "I'll have a good time on Sunday.
"I'm going to try to stay patient in the beginning. If you are within three or four shots entering the back nine, you are always going to have a chance."