Schroeder is in position for his first Senior Tour victory in six years on the circuit. His best previous finish was a tie for second after losing in a playoff in the 1996 Bell Atlantic Classic. He was tied for the lead heading to the final round of that event.
'It would be gratifying to win,' said Schroeder, whose lone PGA Tour victory came in the 1973 Match Play Championship. 'I have two goals for tomorrow -- no mental mistakes and keep working on my putting stroke.'
Schroeder bogeyed the first hole of the day, then ran off seven straight pars before a 15-foot birdie putt at the ninth. He added consecutive birdies to start the back nine and another at 15. An approach in the bunker led to a bogey at 17, but he responded with a 40-foot downhill putt for a birdie at 18 to reclaim the lead.
Schroeder will try to become the third straight wire-to-wire winner of the Emerald Coast Classic, joining Bob Duval and Gil Morgan.
Ahern, whose lone career Senior Tour win came in the 1999 Canadian Open, tied a career low with his round of 64. He played bogey-free golf with four birdies on the front and two on the back, thanks in part to some putting advice from Dave Stockton.
'He spent about 20 minutes with me and it really helped,' said Ahern. 'I made more putts today than I have in a long time. He didn't like my grip, he didn't like my setup and he didn't like my stroke. Other than that I was fine.'
Ahern started a string of three straight birdies with a 30-foot putt on the third hole. His other five birdie putts were inside five feet.
Andy North and Mike McCullough, who each started the day two shots off the lead, managed rounds of 2-under 68 and share third place at 5-under par. McCullough won in Mexico earlier this year.
Bruce Fleisher, Larry Nelson and Jose Maria Canizares are each four shots behind at 4-under and capable of making a run at the top on Sunday.
Fleisher, who carded a 4-under 66, won a total of 11 times in 1999 and 2000 but has yet to win this year. Nelson, who shot a 3-under 67, already has two wins in 2001 and leads the Senior Tour money list. Canizares, who has posted a pair of 68s in the first two rounds, won earlier this month in Los Angeles and is second on the money list.
Leonard Thompson and Sammy Rachels are five shots back at 3-under, while Bruce Summerhays, Graham Marsh, Dave Eichelberger, Tom Wargo and Mike Smith are six off the pace. Smith started the day one shot behind Schroeder, but struggled to a 2-over 72.
Morgan, the defending champion, shot a 1-under 69 on Saturday and is tied for 21st at even-par 140.
Full-Field Scores from the Emerald Coast Classic