Rich Karlis kicked an 18-yard field goal on the final play of the game, leading the Denver Broncos to a come-from-behind 24-21 victory over the San Francisco 49ers today.

San Francisco quarterback Joe Montana had helped give the 49ers a 21-14 halftime lead with a pair of touchdown passes. But early in the fourth quarter, ex-49er quarterback Steve DeBerg threw his second scoring pass of the game, a 37-yarder to Rick Upchurch, and Denver drew to a tie at 21 with 9:29 left to play.

On the next series, Montana passed 30 yards to tight end Charle Young and the 49ers drove to the Denver 36-yard line. But safety Dennis Smith picked off a Montana pass and returned it 30 yards, into 49er territory, with 4:17 left.

The Broncos were successful on two critical third-down situations on that final scoring drive, and a third conversion was decided by a pass interference penalty against San Francisco linebacker Keena Turner. Denver reached the San Francisco one, but Rob Lytle was stopped for no gain on third down. Karlis kicked the winning field goal as the clock ran out.

San Francisco struck quickly for the game's first score. About three minutes into the contest, linebacker Bob Horn tipped a Craig Morton pass and Jack Reynolds intercepted at the Denver 46. On the next play, wide receiver Freddie Solomon beat cornerback Aaron Kyle down the left sideline and caught Montana's 46-yard touchdown throw.

The Broncos drew to a 7-7 tie with 3:38 left in the opening period, when Upchurch ran 67 yards on a punt return for the seventh scoring return of his career.

The 49ers reclaimed the lead less than three minutes later, driving 80 yards for a score. Solomon caught a 26-yard pass and Kyle was cited for pass interference, a penalty that amounted to 36 yards, giving the 49ers the ball at the Bronco one. Jeff Moore swept the right side for the touchdown on the next play.

Denver Coach Dan Reeves replaced Morton with DeBerg, acquired before the 1981 season, and the Broncos made it 14-14 early in the second quarter. A key play on the scoring drive was a 27-yard gain on a short pass from DeBerg to running back Gerald Willhite. DeBerg hit Rick Parros on a four-yard scoring pass with 10:19 remaining in the half.

The 49ers put together a final scoring drive with less than two minutes remaining in the half.