AUGUSTA, Georgia-- Rory McIlroy has teed off in the final round of the Masters, trying to protect a four-stroke lead on a sweltering day.

The 21-year-old Northern Irishman was at 12-under 204 coming into Sunday and playing in the final group with 2009 Masters champion Angel Cabrera, the only player in the top eight with a major title on his resume.

Cabrera started the day at 208, in a group that also included K.J. Choi, Charl Schwartzel and Jason Day. Tiger Woods was a daunting seven strokes off the lead after a disappointing 74 in the third round. Any chance of a comeback by defending champion Phil Mickelson likely ended with a double-bogey at No. 5.

If McIlroy can hang on, he'll be the second youngest champion in Masters history to Woods in 1997.