GLENDALE, Ariz. -- Thanks to Vinny Testaverde, Carolina survived the battle of the backup quarterbacks.
Testaverde hit Steve Smith for a 65-yard touchdown pass, DeAngelo Williams ran for 121 yards and a touchdown and the Panthers defeated Arizona 25-10 on Sunday.
Testaverde threw a touchdown pass for the 21st straight season, extending his own NFL record.
Williams helped ice the game with a late 75-yard run, and he scored on a 13-yard run for the Panthers (4-2), who are 4-0 on the road this year.
John Kasay kicked four field goals for Carolina.
Both teams played with quarterbacks who weren't on the roster last Sunday -- Tim Rattay for Arizona (3-3) and Testaverde for the Panthers.
Rattay was rushed into action when Arizona starter Kurt Warner sprained his left elbow in the first quarter. Warner, a two-time NFL MVP, made his first start of the season in place of Matt Leinart, who is out for the season with a broken collarbone.
The 43-year-old Testaverde signed with Carolina on Wednesday. The Panthers' starter, Jake Delhomme, is out for the season with an elbow injury, and backup David Carr has a sore back.
At 43 years and 335 days old, Testaverde is the third-oldest quarterback to start a regular season game in NFL history. Steve DeBerg started at 44 years, 279 days old on Oct. 25, 1998, and Warren Moon was 44 years, 8 days old when he started on Nov. 26, 2000.
Testaverde completed 20 of 33 passes for 206 yards and a touchdown, and did not throw an interception.
Rattay was 12-of-24 for 159 yards with three interceptions.
The Panthers trailed 10-9 midway through the fourth quarter when Testaverde hit Smith streaking down the right sideline. Smith ran past Cardinals cornerback Rod Hood, caught the ball in stride and cruised into the end zone.
With unfamiliar quarterbacks, both teams scaled back their game plans. A showdown between division leaders was reduced to an ongoing exchange of punts and penalties.
The Cardinals hadn't looked all that formidable with Warner, two of their first three possessions ending with fumbles.
The second came midway through the first quarter, when Panthers defensive end Julius Peppers sacked Warner, causing a fumble that Peppers recovered at the Arizona 37.
Warner, who had completed both of his pass attempts for 21 yards, threw his helmet to the ground as he returned to the bench.
Seven plays later, Kasay kicked a 33-yard field goal to give Carolina a 3-0 lead.
Kasay made it 6-0 with a 43-yarder early in the second quarter.
By then, Arizona had called on Rattay, an eight-year veteran who played in four games last year for Tampa Bay and completed 61 of 101 passes. He played for the San Francisco 49ers for six years before being traded to the Buccaneers.
Rattay looked rusty at the start, fumbling twice in the span of six snaps but recovering both.
Edgerrin James gained 43 of the 80 yards on a touchdown drive that gave the Cardinals a 7-6 lead midway through the second quarter. James went 23 yards for the score, running through a feeble arm tackle by Panthers cornerback Chris Gamble.
It was James' longest touchdown run since he went 34 yards for a score on Sept. 19, 2004, for Indianapolis at Tennessee.
Carolina took a 9-7 lead on Kasay's 24-yard field goal midway through the third quarter.
Arizona answered with a 50-yard field goal by Neil Rackers. Larry Fitzgerald put the Cardinals in Rackers' range by outleaping Gamble to catch a 36-yard pass at the Carolina 32.