Rory McIlory
McIlory lies one under 71 after opening day.Reuters

Rory McIlroy described his opening round at the Masters as a "good day at the office" after finishing one under 71, three shots behind leader Bill Haas.

After a disappointing 2013, the Northern Irishman is looking to add to his 2011 US Open and 2012 US PGA Championship triumphs in Augustus.

After building momentum in his opening five holes he carded four birdies and three bogeys in his opening round but missed a four foot putt on the last to stay at two under.

"The greens are firming up, the wind was all over the place, it was a good day at the office," McIlroy was quoted as saying by BBC Sport.

"If conditions stay the same and they put the pin positions in tough spots, it will be tough to get your ball close, so anything even par, one under, two under is a good score.

"I'm feeling good with my game and came in here relaxed to try and enjoy the week. If I can do that and not get ahead of myself then hopefully I'll give myself a great chance."

After two early birdies inside his first five holes McIlroy's bright start was curbed after taking a drop shot on eight. After taking three putts on the par three 12th he rediscovered some of that early momentum, sinking two more birdies on two par five holes on the back nine.

North Carolina-born Haas leads after the opening day with defending champion Adam Scott just behind him on two under 69.

Justin Rose and Ian Poulter lie off the pace after the first day at four over while Luke Donald suffered a quadruple bogey on the ninth to leave him seven over.

Lee Westwood meanwhile was left dissatisfied with his performance on the opening day, carding a one over 73.

"That's where you're scoring on this golf course," said Westwood.

"It was a bad draw being out last. You sort of sigh when you see the draw. That's as hard as it will play all day. I will be out a bit earlier on Friday and hopefully it's more scoreable."