Phil Mickelson salvaged a bogey after a lost ball and called it the most important hole he played Tuesday, when he shot a 7-under 64 at Ozark National in Ridgedale, Mo., and expanded his lead in his PGA Tour Champions debut.

After his drive was lost in heavy rough on No. 10, Mickelson made bogey with a long putt that gave him momentum.

"I was able to get right back to even par on the back side with a birdie on the next hole, and then I made a couple more coming in," he said.

Mickelson was at 17-under 125 after two rounds, good for a four-shot lead over Tim Petrovic (65) and Rod Pampling (65).

Wednesday's tee times were moved up because of expected bad weather. Mickelson will be in pursuit of the PGA Tour Champions' 54-hole scoring record of 191, shared by five players. He'll need a 65 to break it.

"When I come out tomorrow I'll try to be a little bit more aggressive with the driver and see if I can make a few more birdies," he said.