DENVER -- The Denver Broncos were on such a lucky streak, why not roll the dice?

Showing ultimate confidence in his offense and maybe an equal dollop of distrust in his defense, Mike Shanahan went for the 2-point conversion with 29 seconds left and Jay Cutler hit rookie Eddie Royal over the middle to give the Denver Broncos a 39-38 win over San Diego on Sunday.

"Sometimes you have to go with your gut," Shanahan said. "I just felt like it was a chance for us to put them away. I didn't want to count on the coin flip. I wanted to do it then, and obviously it worked out."

It was the third successful 2-point attempt from a team going for the win instead of a tie in the waning seconds of a game since the 2-point conversion was added in 1994, and the first since Tampa Bay beat Washington 36-35 on Mike Allstott's run on Nov. 13, 2005.

The Chargers (0-2) were both stunned and steamed at their second straight loss in the waning seconds.

The Broncos (2-0) had the ball because an errant whistle had erased Cutler's lost fumble two plays earlier.

Trailing 38-31, the Broncos reached the 1 but on second-and-goal, Cutler reared back to throw and the ball slipped out of his hands, bounced off the grass and into linebacker Tim Dobbins' arms.

"Fumble, I think," acknowledged Cutler, who blamed the slick, new ball.

Referee Ed Hochuli blew his whistle when the ball came out, ruling it an incomplete pass. A review showed that it should have been ruled a fumble. Instant replay rules, however, don't allow the opponent to gain possession in such situations.

"All we can do to fix it is put the ball at the spot that it hit the ground, which is why we moved it back to the 10-yard line and the down counts and it becomes third down," Hochuli said afterward.

That explanation wasn't good enough for Chargers coach Norv Turner.

"On the last play, it was clearly a fumble," Turner fumed. "Ed came over, the official, and said he blew it. And that's not acceptable to me. This is a high-level performance game and that's not acceptable to have a game decided on that play."

The call the Broncos wanted to talk about wasn't the referee's but their coach's.

"You don't play this game to tie," fullback Michael Pittman said. "You play this game to win."

Two plays after his fumble was overruled, Cutler hit Royal from 4 yards to make it 38-37.

With 75,000-plus fans at Invesco Field holding their breath, Cutler again found Royal in the end zone for the winner on the exact same route, his dart splitting three defenders.

The rookie who caught nine passes for 146 yards in Brandon Marshall's absence a week earlier, cradled the winner in his gut, avoiding safety Clinton Hart but not the thrilled teammates who piled on in celebration.

The Broncos actually made the call to go for 2 long before they scored. When the drive began at their 20, Cutler went into the huddle and told his teammates they were going to go for 2 if they reached the end zone.

"That was all he had to say. We had all the confidence that we could do that," Royal said.

And with luck and calls going their way, why not?

Denver also benefited from a twist of fate in the first quarter, when the replay booth's machinery malfunctioned, preventing the officials from being able to overturn a San Diego fumble that led to Denver's first touchdown.

TV replays, which the crew didn't have access to, showed Chris Chambers' left elbow on the grass while he cradled a reception in his right arm as Champ Bailey was trying to strip it away. Hochuli waited the required two minutes, then ruled that the call on the field stood, giving Denver possession at the Chargers 29.

San Diego wasn't charged a timeout, and the Broncos capitalized with Pittman's 1-yard TD dive.

After Denver went ahead on Royal's 2-pointer, the Chargers had one last chance but Philip Rivers' desperation heave into the end zone missed Chambers, who had four catches for 83 yards and two touchdowns.

Cutler completed 36 of 50 passes for a career-best 350 yards and four TDs and enjoyed the return of Marshall, who set a franchise record with 18 catches for 166 yards in a magnificent return from his one-game suspension.

Marshall's receptions were two shy of Terrell Owens' NFL record of 20 set for San Francisco against Chicago earlier this decade.

With LaDainian Tomlinson slowed by a jammed right big toe, his backup, Darren Sproles had a career day, piling up 317 all-purpose yards on 14 touches, including a 103-yard kickoff return for a touchdown in the first half and a 66-yard catch-and-run for the go-ahead score with 4:22 remaining.

Sproles took a short pass from Rivers, who threw for 377 yards and three TDs, and raced through the Broncos' befuddled defense to put the Chargers on top 36-31. Legedu Naanee's catch for the 2-point conversion made it 38-31.

That came three plays after Cutler's only big mistake of the game -- that counted, at least.

The Broncos were heading in for a score when rookie cornerback Antoine Cason intercepted Cutler's pass in the end zone, setting up Sproles' 66-yard jaunt that the Chargers still swear should have iced it.

Notes

• According to STATS Inc., seven teams have gone for 2 when down by a point inside the 2-minute warning of the fourth quarter since the 2-point conversion was instituted in 1994. Three of those were successful.