Allen, who was among three players tied for first after Friday's opening round, is at 10-under 134 after 36 holes. Jay Don Blake and John Cook each shot 5-under 67 Saturday and are tied for second at 9-under for the tournament.
David Peoples, who was tied for first after the opening round, shot 2-under 70 Saturday and is tied with Mark O'Meara (69 Saturday) for fourth. Friday's third co-leader was Mark Calcavecchia, whose even-par 72 Saturday dropped him into a tie for ninth at 6-under with one round to play.
Birdies at the first and fifth holes Saturday had Allen still tied with Peoples and Calcavecchia for the lead before he dropped in a 20-footer for birdie at No. 8 to take sole possession of first.
He added birdies at 10 and 14 but ended up in a fairway bunker on the par-5 15th hole and settled for bogey there. Three pars the rest of the way finished his 68.