Allenby opened with four birdies in his first six holes and closed with three in his last four during a bogey-free round. His 63 tied the record at the Mines Resort and Golf Club in Selangor, Malaysia.
Tour rookie Jhonattan Vegas is in second at 7-under after he had birdies in each of his last four holes. Fredrik Jacobson, who had an eagle at the par-4 15th, is third at 6-under 65. Three more golfers are at 5-under.
Allenby, who was in the third group out Thursday, had back-to-back birdies at Nos. 2-3 and again at 5 and 6. He got to 5-under on the day with a birdie at No. 11 and jumped up the leader board with birdies over 15-17.
"I hit it very well," Allenby said. "Really just hit one bad tee shot at the last but I still managed to a make a good up and down for par.
"Overall, I'm very happy with the way I'm playing and the way I'm hitting and it was just nice to score well."
The tournament in Malaysian is the first unofficial event of the PGA Tour's off-season.