Phil Mickelson leads by three shots with four holes to play in the 70th Masters Tournament, closing in on his second green jacket.

The 2004 champion is 7-under through 14 holes. Playing partner and 1992 champ Fred Couples is tied with Tim Clark, Chad Campbell, Retief Goosen and Jose Maria Olazabal for second place at 4-under.

Couples helped give Mickelson a comfortable cushion. He missed two putts inside six feet to make bogey instead of birdie at No. 14. The 46-year-old, who is trying to become the oldest winner in Master history, also missed two short putts early in his round.

Olazabal moved into contention with a 6-under 66 Sunday, the lowest round of the tournament. Olazabal, a two-time Masters winner, got to 5-under for the tournament with an eagle at the par-5 15th but bogeyed the par-3 16th and parred out.

Favorites Tiger Woods and Vijay Singh haven't been able to find momentum in their final round. Woods opened at 2-under and was 3-under through 16 holes, thanks to a birdie at No. 16. He nearly aced the par-3 -- the site of his memorable chip in a year ago -- with the ball landing just inches left of the cup.

Singh, meanwhile, opened his final round with a bogey to fall to 1-under. He made three birdies in a four-hole span to get to 4-under with nine holes left but bogeyed No. 16 and is four shots behind Mickelson.