Pat Perez birdied his final two holes to finish with a two-under-par 70 and take a four-stroke lead after three rounds of the Pebble Beach National Pro-Am.
Tied for second place are former double US Open champion Lee Janzen and Matt Gogel.
Now Perez, a rookie who has missed the cut in his last two events, must deal with the pressure in the final round.
‘‘I’m trying not to do anything stupid,’’ the 25-year-old said. ‘‘Four shots is nothing, I have to go after the pins. If you are not hitting it perfect or close to it, it’ll get you.’’
Gogel, who lost out from a similar position in his rookie season two years ago, joked: ‘‘Four shots, we all know leads can disappear very quickly.
‘‘No ill will toward Pat, he is obviously playing well. If he continues to play the way he is playing, I don’t think it will be a contest.’’
Perez’s 15-under-par 201 is five shots better than Andrew Magee and six ahead of Jerry Smith.
World number one Tiger Woods is in a tie for 35th, 13 shots off the pace.
Among the notable players missing the cut of even-par 216 were former champions John Cook (225), Peter Jacobsen (221), Davis Love III (221), Phil Mickelson (229) and Mark O’Meara (217).