Graham Marsh, Dave Stockton and Hale Irwin were tied for the lead and 14 players were within four shots after Saturday's second round of the Senior Tour American Express Invitational.
The trio of leaders finished play at the TPC at Prestancia at 11-under-par 133.Bob Murphy, Tom Weiskopf, Isao Aoki and Frank Conner were at 10 under.
"Normally, when you're in the lead going into the final day, you don't have two guys tied with you, four more one back and I don't know how many close," Irwin said. "But I will say it's going to be exciting."
Both Irwin and Marsh shot 5-under 67s Saturday, while Stockton came in with a 68.
Irwin, who has yet to make a bogey in two rounds, had five birdies, and Stockton had five birdies - three in a row on Nos. 5, 6 and 7 - and one bogey. Marsh finished with seven birdies and two bogeys.
"The name of the game right now is who makes putts," Irwin said. "I'm playing well, not fantastic, but it's not good enough to get ahead of the pack."
In perfect weather and with the course offering almost no rough, 53 of the 78 players finished under par for 36 holes.
"It's going to be a shootout," Marsh said. "You can't count guys out who are 6- or 7-under. If they start to run hot, they can get right back in it. It should make for some lively entertainment."