Michael Allen shot a 4-under 67 to take a five-stroke lead after Saturday's second round of the Champions Tour's Encompass Insurance Pro-Am.
Allen played the front nine in even par, then birdied the par-3 11th and made a 40-foot eagle putt on the par-5 12th. He finished with a birdie on the par-4 18th to reach 9 under at TPC Tampa Bay.
Allen won the 2009 Senior PGA Championship for his lone victory on the 50-and-over tour.
Bernhard Langer, Sandy Lyle, Corey Pavin and Olin Browne were tied for second. Langer and Pavin shot 71, Lyle had a 69, and Brown a 66.
First-round leader Bruce Fleisher struggled, shooting a 78 to finish at 1 over. The 63-year-old Fleisher shot a 65 on Friday.
Tom Watson dropped out because of an injured right hand. He shot a 77 on Friday.
Watson has had an issue with the arm recently, which he said earlier in the week has translated into a weak hand.
Andy Bean and Wayne Levi also withdrew Saturday because of back injuries. Nick Price (elbow) and Tommy Armour III (shoulder) both departed Friday.
After Pavin got to 7 under with a birdie at 14, he bogeyed the next three holes.
Fleisher had bogeys on Nos. 1 and 3, and a triple bogey on the par-4 fourth hole after hitting two balls into the water. He played even par on the back nine.
Chien Soon Lu, one shot off the lead entering Saturday, dropped to 3 over after a 79.
Kenny Perry, coming back from a viral infection, had eight birdies en route to a 67. He was 6 under before double bogeys at 15 and 18 left him at 3 under.
