Mark Calcavecchia shot a 3-under 69 on Saturday to increase his lead to four strokes after the second round of the Champions Tour's AT&T Championship.
Calcavecchia, three strokes ahead after the completion of the rain-delayed first round, had an 8-under 136 total on TPC San Antonio's Canyons Course.
He had 26 putts, one-putting the final five greens and six of the last seven.
"I got away with one," said Calcavecchia, the runner-up last year. "I didn't play near as good as yesterday, for some reason. It was easier conditions than yesterday. I hit it a little bit crooked. To shoot 3 under, though, considering I didn't hit it as near as good as yesterday, was really good."
Kenny Perry was second after his second straight 70.
"The ball's kind of in Mark's court," Perry said. "If he plays a good round, I'm not going to catch him. Mark has never changed. He's always been a flag-hunter."
The tournament is the final full-field end of the year. The top 30 on the money list will qualify for the Charles Schwab Cup Championship next week at Desert Mountain in Scottsdale, Ariz.
Calcavecchia won the Montreal Championship in June for his second career victory on the 50-and-over tour. That came before surgery to repair ligament damage at the base of his right ring finger. On Saturday, he said his back bothered him more than his finger.
"My back was a little bit spasmy," Calcavecchia said, "and when that happens I hunch over a little bit to protect it. When I do that I get both-way misses."
He missed the fairways by big margins to the right on Nos. 14 and 15, but saved par.
After a hard 6-iron from the par-3 16th tee gave him a 3-foot birdie putt, Calcavecchia tried to compensate for going right with the driver on the previous holes. So his driver on the short, reachable par-4 17th went 50 yards left. It went so far off line he took out another ball and hit a provisional from the tee.
"I thought it was going to be in the bushes, rocks, whatever you call it here," he said. "I was surprised to see that it hadn't got to the bad stuff yet. It was in the light weeds and a pretty good lie all in all."
So he flipped a wedge to 10 feet and made the birdie putt.
Brad Faxon and Estaban Toledo were 3 under after 67s. Chip Beck (71), David Frost (71), Fred Funk (69), Bernhard Langer (68), Mark Wiebe (70) and Willie Wood (72) were 2 under.
Faxon eagled the 535-yard, par-5 15th. His 17-degree hybrid second shot from 262 yards raced onto the putting surface and gave him a tap-in eagle.
"It took the slope like a race car on the track," Faxon said. "But to win, you have to do something spectacular and hope that someone throws up on themselves."
John Cook, a two-time winner in the event who finished third last year, withdrew because of back pains after completing his first round in the morning. Fred Couples, this winner last year, skipped his title defense because of back problems.