The Super Bowl’s supposed marquee matchup was no contest. The Seattle Seahawks’ defense dominated the Denver Broncos’ offense Sunday evening, setting the tone from the outset as the Seahawks coasted to the first Super Bowl triumph in franchise history.

The Broncos had an errant snap leading to a Seattle safety on the game’s first offensive play. Denver didn’t manage a first down until it already trailed 15-0 in the second quarter. The Seahawks intercepted two first-half passes by Broncos quarterback Peyton Manning, with linebacker Malcolm Smith returning one of them for a touchdown, and never faltered on their way to a 43-8 victory.

The Denver offense had four turnovers in all, including lost fumbles by wide receiver Demaryius Thomas in the third quarter and Manning in the fourth quarter. Manning ended up throwing for 280 yards on 34-for-49 passing. He actually set a Super Bowl record for completions. Thomas’s 13 catches also were a Super Bowl record. But by the time Manning threw a touchdown pass to Thomas as time expired in the third quarter, Seattle had built a 36-0 lead.

“Our whole defense, top to bottom, they played lights out,” Seahawks wide receiver Percy Harvin said.

It was supposed to be a compelling confrontation between a Broncos offense that ranked first in the NFL during the regular season and the Seahawks’ top-ranked defense and in particular between Manning and a Seattle secondary known for its aggressive, physical play. Manning set single-season NFL records for passing yards and touchdown passes this season and won his record fifth MVP award Saturday night. But he and the Broncos had no answers for the defense they faced Sunday.

Smith, who was named the game’s MVP, said he expected the game to unfold just as it did.

“We feel like we play with a level of intensity other teams have to match,” Smith said. “We liked this matchup. We felt they would have to deal with us.”

Added cornerback Richard Sherman: “I think it was more about our players playing well than Peyton. . . . You can never really expect it. But I wasn’t shocked. I expected us to stand up.”

Manning’s offensive line played nearly flawlessly when the Broncos beat the New England Patriots in the AFC title game two weeks earlier. That certainly wasn’t the case against the Seahawks. Seattle’s pass rushers made Manning move around in the pocket and forced him into mistakes. Seahawks defenders put some heavy hits on Broncos receivers after catches. Cornerback Byron Maxwell knocked the ball from Thomas’s hands on the wide receiver’s third-quarter fumble.

“I wasn’t surprised at all,” Seattle linebacker Bobby Wagner said. “Watching the film during the week, they hadn’t played a defense like us that flies around like we do, that hits like we do. . . . We thought we could hold them to zero points if we played our game.”

Denver’s first major mistake was an unforced error. Manning lined up in shotgun formation for the Broncos’ opening play. He was moving toward the line of scrimmage and wasn’t ready for the ball to be snapped to him when center Manny Ramirez sent the snap sailing over Manning’s head. The ball rolled into the end zone, where running back Knowshon Moreno fell on it for a safety. The Seahawks had the fastest scoring play in Super Bowl history, getting on the scoreboard after 12 seconds.

Manning’s first interception came on a pass lobbed over the middle directly to Seahawks safety Kam Chancellor late in the first quarter. That set up a second-quarter touchdown for Seattle. Manning’s second interception came when his arm was hit by Seahawks defensive end Cliff Av­ril on a throw. The pass went high into the air. Smith made a decisive move toward the ball. Moreno didn’t. Smith got the interception and dashed 69 yards for a touchdown.

When the Broncos gambled, it backfired. Coach John Fox left his offense on the field on fourth and two from the Seattle 19-yard line late in the first half. Manning threw an incompletion on a pass deflected by defensive end Chris Clemons.

“We did exactly what we said we were gonna do,” Chancellor said.