The Avengers will need another week to secure a home game in the Arena Football League playoffs.
On Saturday, Los Angeles lost to Arizona, 52-46, in overtime when Rattler quarterback Sherdrick Bonner scrambled five yards for a touchdown before 13,120 at Staples Center.
The Avengers trailed, 46-38, but rallied to tie the score at the end of regulation. Quarterback Tony Graziani took the snap with two seconds remaining and found Greg Hopkins for a two-yard touchdown pass. He then threw a two-point conversion to Russell Shaw to force overtime.
Los Angeles had the first possession but failed to score, setting up Bonner's heroics.
The loss dropped Los Angeles (7-5) into a third-place tie with Dallas in the West Division.
Arizona (9-3) trailed, 17-16, at the half, but scored three times in the third quarter to take a 36-24 lead. Los Angeles fought back but needed to recover a Rattler fumble on the Los Angeles 23-yard line to set up the final drive that tied the score and forced overtime.
Arizona took a 9-0 lead in the second quarter as the Avenger offense sputtered. But Graziani smoothed things out with a 12-yard touchdown pass to J.J. Washington. Later, Chad Dukes rumbled in from two yards out to put Los Angeles ahead, 14-9.