Bears' stunning comeback

Given little chance of upsetting unbeaten Chicago, the Cardinals (1-5), backed by a raucous crowd at the University of Phoenix Stadium, stormed to a 20-0 halftime lead before the Bears came out of hibernation to improve their perfect record to 6-0.

"We just kept playing hard and never gave up and made plays when we had to," Bears linebacker Brian Urlacher told a television sideline reporter.

"We never had doubt. At halftime we knew we were going to come out and play hard. We never give up, our coach won't let us."

A shoddy offensive performance by the Bears was cancelled out by a brilliant defense, that returned two fumbles for touchdowns and limited the Cardinals to a field goal in the second half.

The Bears' top-ranked offense, which has averaged over 31 points a game, had a miserable night, failing to score and giving up six turnovers as quarterback Rex Grossman tossed four interceptions and fumbled twice.

But the Chicago defense, led by middle linebacker Urlacher, came to the rescue with a stirring second half stand.

Even after Hester took a punt and twisted his way into the end zone to put the Bears 24-23 ahead with just under three minutes remaining in the fourth quarter, the Cardinals had one last chance to seal victory.

With the crowd on its feet, rookie quarterback Matt Leinart marched the Cardinals deep into Chicago territory to set up a 41-yard field goal attempt by Neil Rackers.

But Rackers, who had already kicked three field goals, including another 41 yarder, watched in disbelief as his game-winning attempt drifted wide with 53 seconds left on the clock.

The second-half collapse overshadowed an inspired effort by Leinart, who was making just his second career start.

The Heisman Trophy winner from USC displayed veteran poise against one of the NFL's most feared defences, throwing first quarter touchdowns to Bryant Johnson and Anquan Boldin, who hauled in 12 catches for 136 yards.

Two second quarter field goals from Rackers and another by the Cardinals kicker in the third had Arizona in control at 23-3.

But with just two seconds to go in the third the Cardinals began to unravel when Mike Brown recovered a Leinart fumble and returned it for a touchdown.

The Bears defence scored again early in the fourth, after Urlacher ripped the ball away from Edgerrin James and Charles Tillman picked it up and rumbled 40 yards into the end zone to trim the Arizona lead to 23-17.