IRVING, Texas — Ron Dayne was ready, and it showed.

Despite not having carried the ball in nearly two months and not knowing he’d even play until a few hours before kickoff, Dayne responded with his best performance in four years.

Filling in for injured Tatum Bell, Dayne rumbled 55 yards on the second play of overtime and Jason Elam followed with a 24-yard field goal to give the Denver Broncos a 24-21 victory over the Dallas Cowboys on Thursday in the kind of tight, tense game expected in a clash between first-place teams.

‘‘The coaching staff gave me a chance and they believed in me,’’ Dayne said. ‘‘I was glad I got this opportunity to show Coach that I wasn’t a bust.’’

Dayne ran for 98 yards, his most since Sept. 30, 2001, and the third-most of his career. He also scored his first touchdown since the 2004 opener, when the 1999 Heisman Trophy winner was still with the New York Giants — all because a bruised chest forced Bell to sit out.

Dayne joined the Broncos this offseason for the minimum salary in hopes of reviving his career in an offense that consistently features one of the NFL’s best rushing attacks. He wound up being active only five of the first 10 games and came into this one without a carry since Oct. 2. He’d gained only 53 yards all season.

‘‘I never lost confidence in my ability,’’ he said. ‘‘I knew I could play if I found the right situation and the right opportunity.’’

Alternating series with Mike Anderson, Dayne had a season-best run of 14 yards on his first carry and a 16yard touchdown run in the third quarter.

Denver (9-2) never trailed in winning its fourth straight, but the Broncos were hardly in control. Their running game struggled until Dayne’s big burst and Jake Plummer threw his first interception since Week 2. Still, they improved to 3-2 on the road to maintain hopes of catching unbeaten Indianapolis for home-field advantage in the AFC playoffs.