LOS ANGELES — When Phil Mickelson tees off with a one-stroke edge to start today's final round of the Northern Trust Open, it will mark the 26th time in his career that Mickelson has held the 54-hole lead.

Of the previous 25 times, Mickelson has successfully closed the deal 18 times. However, one of Mickelson's seven final-round failures came at Riviera a year ago, when he lost to Charles Howell III in a playoff after making bogey on the final hole.

Like 2007, Mickelson will take a one-stroke lead into today's final round, but unlike last year, only one player, Jeff Quinney, appears to be within realistic striking distance.

After a third-round 1-under 70, Mickelson finds himself at 11-under 202. Quinney, who started the third round four shots down to Mickelson, is at 10-under 203, thanks to a 4-under 67 on Saturday, which included a hole in one on the par-3 sixth and a dramatic 35-foot birdie putt on 18.

John Rollins will join Quinney and Mickelson in the final group, but he's five shots behind Mickelson.

With the rest of the field so far behind, today's final round could potentially turn into a match-play like competition, that is if the two former Arizona State stars play well.

"If we go out and shoot under par, it will be tough for guys to catch us and we'll have a good match," Mickelson said. "If we don't play well, we let everyone back in."

Mickelson admits it's a better situation than in 2007 because there are fewer quality players in the chase. He also said he's comfortable as a front-runner.

"Tomorrow we'll go head to head and if I can just tie him, the tie goes to me," Mickelson said. "That's a nice thing about having a shot in hand. I would like to have increased my lead. Unfortunately, I didn't do that."

Part of the reason Mickelson was unable to build on his four-stroke lead after 36 holes was his spotty play on Saturday. He started the day by pushing his drive into the right rough, and while he was able to make par, he lost a stroke to Quinney, who made birdie.

Mickelson bogeyed the par-3 fourth hole when his par putt lipped out, dropping his lead to two strokes.

A birdie by Quinney at the fifth hole dropped Mickelson's advantage to one shot. A few minutes later the lead was gone after Quinney knocked a 7-iron into the 163-yard, par-3 sixth hole into the cup for an ace, leaving him at 10 under. To his credit, Mickelson hit a strong shot of his own into the sixth green, sticking his 8-iron to 6 feet, where he converted the birdie putt.

"I thought that was as good a response as I could have expected," Mickelson said. "I thought that was a big 2 for me."

When the ball left his club, Quinney wasn't too comfortable with the shot, thinking it might even end up in the bunker in the middle of the green. It hit on the slope next to bunker and sucked back and into the hole.

Quinney admitted he wasn't sure it went in until the gallery around the green erupted.

With his adrenaline pumping, Quinney searched for his caddie to celebrate, but their attempt at a chest bump failed.

"It was almost like a touchdown end-zone dance or something, but basically we need to get that organized with my caddie and plan a little better," Quinney said. "You don't know whether to hug or high-five. Had (an ace) at the Hope last year. It's an amazing feeling."

While his post-ace celebration might need some work, his golf game was firing on all cylinders for most of the day on Saturday. While Quinney admitted to being a little more nervous than normal because of playing with the world's No. 2-ranked player, he said his birdie on the first hole calmed him down.

He had a few back-nine hiccups, with bogeys on 11 and 16, but overall the second-year pro played steady throughout the round.

"I felt really comfortable," Quinney said. "I actually drove it really well. That's been the part of my game I've been struggling with, but I hit my driver confidently today."

Part of that confidence comes from having played so well on the West Coast the last two years. As a rookie in 2007, he had four top-10 finishes on the West Coast swing, including tying for ninth at this event.

With so much success and no wins to show for it, Quinney isn't sure if he's due for a breakout performance.

"I don't know if I'm due, but I definitely know I want to have a chance coming in tomorrow," Quinney said. "(Mickelson's) going to bring a lot to the table, and I've got to bring my best. ... He's not going to hand it to me. I've got to go out and earn it."