DENVER (AP) — Ben Roethlisberger was missing reads and his receivers, and it had the Pittsburgh Steelers reeling in the first half.

It was all so very unlike Roethlisberger. The situation only got worse after halftime, when his sack and fumble led to Robert Ayers' long touchdown return.

If Big Ben was rattled, he didn't show it, needing just four plays to march the Steelers 80 yards for the touchdown that put them ahead for good in their 28-10 rout of the Denver Broncos on Monday night.

"I kind of rushed a little bit," admitted Roethlisberger, whose team has now won five straight. "I think offensively we've got a long ways to go. We made a lot of mistakes and we've got to keep searching for the ceiling because we can't play the way we've been playing and continually beat good conference teams."

There definitely was a good/bad element to Roethlisberger Monday night.

The good came with a pair of 3-yard touchdown passes to Hines Ward and another to rookie wideout Mike Wallace.

The bad was losing a fumble when he was hit from behind by Kenny Peterson, the ball flying free and Ayers scooping it up for a 54-yard TD. Roethlisberger also threw an interception with the Steelers poised to put more points on the board when Andre' Goodman stepped in front of a pass that sailed behind Ward.

But when the Steelers (6-2) needed him most, Roethlisberger delivered.

"That guy you can't ever stop," Wallace said. "He just makes things happen."

There was no argument from the Broncos, who dropped their second straight after opening the season 6-0 under rookie coach Josh McDaniels.

"Great quarterback," Goodman said. "He doesn't panic, no matter what the situation is. His head is always in the game."

Part of the reason for the Steelers' second-half turnaround was trying out a new tactic — the nonstop no-huddle. The Broncos certainly weren't ready for it.

"Caught us off guard a little bit," Goodman said.

The Broncos shouldn't have been surprised; the Steelers talked all week about employing the no-huddle at Denver.

The Steelers received a lift from safety Tyrone Carter, who intercepted a Kyle Orton pass in the second quarter and raced 48 yards for a touchdown that gave Pittsburgh a 7-3 halftime lead.

On the bench, safety Ryan Clark was loving it, jumping up and down in celebration.

Carter was filling in after the team elected to hold Clark out rather than take a risk with his health. Clark nearly died after a game in the Mile High City two years ago because of a rare blood disorder that is aggravated by playing in high altitude. Clark had his spleen and gall bladder removed in separate operations following the Steelers' loss in Denver in 2007.

He couldn't have been happier for his fellow defensive back.

"I might be like Wally Pipp," Clark said, referring to the Yankees first baseman who was replaced by Lou Gehrig in 1925. "I'd better get back fast."

Carter finished off the night in grand style — picking off another Orton pass.

"I just like the opportunity to step up and show my teammates that I can make plays when my number is called," Carter said.

For the Broncos, it was another dreary second half — and that was once their forte.

The Broncos prided themselves on halftime adjustments that worked like magic the first six weeks as they outscored opponents 76-10 after the break during the six-game winning streak.

They've been outscored 45-14 in the last two games.

"We are not going to get down," linebacker Andra Davis said. "We are going to stay positive. We are going to continue to encourage each other, and play hard for one another and get back on the winning track."

One of the few bright spots was the play turned in by Ayers, who set the franchise mark for the longest scoring fumble return by a Broncos rookie.

Not that he was particularly thrilled about the distinction.

"Of course it was a big moment for me," Ayers said. "But I'll trade that in for a win any day."