Augusta - Jordan Spieth stumbled with a bogey at the par-3 fourth hole Saturday but remained five strokes ahead of his nearest rivals in the third round of the Masters.
The 21-year-old American, who set a Masters record with a 36-hole total of 14-under 130, birdied the par-5 second but dropped a shot two holes later to stand on 14 under.
Three-time Masters champion Phil Mickelson birdied three holes in a row starting at the second to reach nine under, level for second with fellow American Charley Hoffman.
Mickelson, a 44-year-old left-hander, took the 2004, 2006 and 2010 Masters and also won the 2013 British Open and 2005 PGA Championship.
England's Paul Casey and American Dustin Johnson, who had an unprecedented three eagles in his second round, shared fourth on eight under with world number one Rory McIlroy, seeking his third major win in a row to complete his career Grand Slam, another shot adrift.
Tiger Woods was at six-under after going four-under 32 on the front nine and starting his back nine with two pars.