DENVER -- The Denver Broncos always believed quarterback Case Keenum could bounce back from mistakes and show some mental toughness when it was needed in a game.

But maybe they didn’t really want to see him do it every weekend.

Keenum, whom the Broncos signed to a two-year, $36 million deal this past offseason, has led game-winning, fourth-quarter drives in each of the Broncos’ two wins to open the season. Sunday, in a 20-19 win over the Oakland Raiders, Keenum cut it as close as possible as the Broncos went 62 yards in 10 plays in the game’s final two minutes.

Brandon McManus kicked a 36-yard field goal to win the game with six seconds remaining. That was an encore from the opening weekend of the season when the Broncos put together a fourth-quarter drive to defeat the Seattle Seahawks 27-24.

“I mean, anytime you have a game-winning drive in the fourth quarter, it feels pretty awesome," Keenum said. “Last week was fun. This week was a lot of fun. They are all special. This is incredible. To start in my first two games here with, you know, wins like that, when you have adversity going, not playing well in the first half, to come out and play like we did in the second half ... we just kept fighting. We've got fighters in that locker room, you know. We want it bad."

Keenum finished Sunday’s game a rather pedestrian 19-of-35 for 222 yards and an interception -- he was just 5-of-11 for 38 yards and the interception in the first half. But on the 10-play, 62-yard drive to win the game, Keenum completed three passes for 34 yards and had a 7-yard run.

It capped a 10-point quarter for the Broncos and enabled them to overcome a difficult start by the offense, a balky stumble out of the gate Sunday that included Keenum’s interception.

“That’s our guy," said Broncos linebacker Von Miller.

Keenum threw three interceptions in the team’s opener against the Seahawks, but it was part of a 329-yard, three-touchdown day for Keenum. Sunday’s game, however, had a far different feel for much of the day as the Broncos' offense struggled mightily in the first half with just one first down by halftime and four three-and-outs in their six first-half possessions, with a five-play drive ending on a Keenum interception and the sixth possession ending at the half.

Keenum’s interception came early in the second quarter on a play that began on the Raiders’ 18-yard line.

“I don't know if I connected with many people in the first half," Keenum said. “... But it's hard to get the ball to anyone when you don't have that many plays."

Keenum also called his interception an “idiotic mistake," as he has thrown seven interceptions in his past four games -- two playoff games with the Minnesota Vikings last January included.

But while the Broncos don’t want turnovers, they did sign Keenum because they believed he could rebound from the rough spots in games, something all three of their quarterbacks (Trevor Siemian, Brock Osweiler and Paxton Lynch) struggled with last season when they threw 22 interceptions.

Keenum completed a 4-yard pass to tight end Jeff Heuerman on a third-and-3 on the final drive and later found wide receiver Tim Patrick for a 26-yard catch-and-run play that put the ball on the Raiders’ 18-yard line for McManus’ kick.

“We meet every Friday about two-minute offense, being smart with the ball, and our guys came through," said Broncos coach Vance Joseph. “It was fun to watch."

“We talk about it all during the offseason, we’re talking about two-minute [offense]," Keenum said. “All during the week we are talking about two-minute. You just need time and downs. They brought the kitchen sink at us. There was pressure after pressure. The O-line just played their guts out and the guys made some plays down the field. It was fun to watch."