Gradkowski replaced an ineffective Jason Campbell after halftime and led the Raiders to three scoring drives and a 16-14 victory over the St. Louis Rams in the home opener on Sunday.
Gradkowski threw a 4-yard touchdown pass to Louis Murphy, Darren McFadden ran for 145 yards and Sebastian Janikowski kicked three field goals to give Oakland (1-1) its first win in a home opener since 2004.
Cable turned to Gradkowski midway through last season to take over from draft bust JaMarcus Russell. Gradkowski breathed life into Oakland's inept offense, leading the team to victories over Cincinnati and Pittsburgh before being sidelined by a knee injury.
Gradkowski never got the chance to win the job this season as Oakland traded for Campbell and made him the starter. Gradkowski tore a pectoral muscle in the offseason and injured his groin early in training camp.
Campbell struggled in a 38-13 season-opening loss at Tennessee and was pulled at halftime of this game. He was 8 for 15 for 87 yards and an interception on his final pass as Oakland trailed 7-3.
The fans started chanting for Gradkowski late in the first half and the calls of "Bruuuuce!" continued each time he took the field in the second half.
Gradkowski completed his first three passes, building even more crowd support with each throw. His 26-yard completion to Murphy set up a 41-yard field goal by Janikowski that made it 7-6.
After the Raiders stopped the Rams on a three-and-out the next possession, Gradkowski drove Oakland 83 yards to a score on the floater to Murphy.
The offensive success appeared to give a boost to a defense that struggled to slow down Steven Jackson in the first half. St. Louis gained only 17 yards and one first down — on a personal foul by Tommy Kelly — in the first 26 minutes of the second half.
Bradford finally got the Rams moving after Jerome Murphy intercepted a pass from Gradkowski with just over 4 minutes remaining and the Rams trailing 16-7. It took just 47 seconds for Bradford to drive the Rams 59 yards, making it 16-14 with a 17-yard TD pass to Clayton with 3:18 remaining.
A personal foul on Fred Robbins and a 13-yard pass from Gradkowski to Murphy on third-and-7 helped Oakland run out the clock.
The play in the first half was reflective of two teams that have struggled to win any games in recent years. Both teams missed makable field goal attempts in the first quarter, with Josh Brown missing wide right from 36 yards for St. Louis and Janikowski missing wide left from 46 yards.
Bradford played conservatively in the first half, throwing only four passes to wide receivers. He converted one of those into a touchdown when he connected from 7 yards with Clayton to give St. Louis a 7-0 lead.
The Raiders got their only points of the half on a 38-yard field goal by Janikowski on a drive that stalled when rookie Jared Veldheer was beat by James Hall for a sack.