Bernhard Langer shot 2-under 70 on Saturday to maintain a 3-stroke lead through two rounds of the ACE Group Classic.
Langer, who won this tournament in 2011, is 12-under 132 through 36 holes. He will aim for his 17th Champions Tour victory on Sunday.
"I hit a lot of great shots, gave myself lots of opportunities, really thought I had a chance to be maybe five or six in front, but just as I said, I didn't make a lot of putts," said Langer. "But hey, there's another day tomorrow."
Chien Soon Lu fired a 68 to move into a tie for second place with Tom Pernice Jr. (69) at 9-under, while Mark O'Meara is alone in fourth after a second- round 69 at the windy Club at TwinEagles' Talon Course.
Mark Wiebe (70), Jay Don Blake (71) and John Huston (71) share fifth place at 7-under, one stroke ahead of Fred Funk (71), Jeff Freeman (70) and Gene Sauers (67).
Rocco Mediate (67), a winner last week in his Champions Tour debut at the Allianz Championship, Steve Elkington (70) and John Cook (68) are tied for 11th at 5-under. Cook won the season-opening Mitsubishi Electric Championship in Hawaii.
Defending champion Kenny Perry is 3-under through 36 holes. He defeated Langer by five strokes a year ago.
Eight-time PGA Tour victor Bob Tway was three shots off Langer's pace after one round, but he stumbled to a 79 on Saturday and dropped into a tie for 39th.
Lu saw his 4-shot overnight deficit quickly jump to six when he double-bogeyed the first, but he rebounded with a stretch of five birdies in six holes to vault up the leaderboard.
After closing his outward nine with a pair of pars, Lu birdied Nos. 10 and 11 to pull within a stroke of Langer. But he failed to get any closer and finished with six straight pars and a bogey on the last to hit the clubhouse at 9-under.
While Langer didn't duplicate his sparkling, opening-round 62, he did manage to maintain his lead with steady, bogey-free play on Saturday.
A birdie on the first got Langer to minus-11, but he didn't pick up another shot until his inward nine, when he birdied the par-4 14th to reach 12-under. He closed with four straight pars to maintain the edge.
"I got off to a good start birdieing the first hole, actually played some good golf today, had several chances, a little bit unlucky with some of my putts," continued Langer. "There's a bunch of them that just went over the edges and none of them dropped. Very happy that I didn't make a bogey in these tough conditions."
Pernice, who hasn't won on the Champions Tour since capturing the 2009 SAS Championship in his debut, carded four birdies against a bogey to remain within striking distance.
NOTES: Lu is seeking his first Champions Tour victory ... Andy Bean withdrew on Friday ... Last year, Perry fired rounds of 64-62-70 to earn the 5-shot win ... This year's tournament marks the 26th anniversary of a Champions Tour event in Naples. On the current schedule, only the AT&T Championship in San Antonio, Texas, has been played longer in the same city (28 years).