PITTSBURGH—Mark Sanchez told the motorcycle story this week.

It was the second-year Jets quarterback's first meeting with the team hierarchy, before he officially became their draft pick last June. Walking out of the restaurant where they ate, he spied a motorcycle next to the Jets brass' car. He teasingly went up to the bike and grabbed the helmet, as if he were about to go for a ride.

Jets QB Mark Sanchez eludes the Steelers' Casey Hampton. European Pressphoto Agency

Mr. Sanchez was indeed the guy on the motorcycle Sunday night. If only his defense and his run game didn't wait until the second half to get on their own bikes.

Mr. Sanchez will have to wait on playoff road win No. 5, the most ever by an NFL quarterback—but not because of anything he didn't do. He led his sixth-seeded, Wild-Card team on a tremendous charge in the second half Sunday, and he nearly pulled off the unthinkable—a third straight road win en route to the Super Bowl.

But even as the Jets ultimately fell 24-19 to the Steelers in their second straight AFC title game, Mr. Sanchez's play suggested he's done playing second fiddle in the quarterback game.

"It hurts. As a competitor, it hurts,'' he said after completing 20 of 33 passes for 233 yards and two touchdowns on a night when he did not throw a single interception. He spent the second half stepping up in the pocket, coolly using the whole field and his full arsenal of pass-catchers. If only he'd gotten to do that in the first half.

"We started slow, and it's really too bad," Mr. Sanchez said. "To come out flat against such a great team, it doesn't work.''

The Jets defense was absolutely gutted in that first half, beginning with the Steelers' opening drive. They ran 16 plays, took 9:06 off the clock and yielded to Mr. Sanchez roughly half an hour after he'd thrown his last pregame warmup toss.

In jumping out to a 24-0 lead, the Steelers rang up 231 yards, 136 of them on the ground, as the Jets defense repeatedly missed tackles, letting the Steelers make plays well after they were seemingly down. The Jets' defense gave Mr. Sanchez little time to work with. But Mr. Sanchez did have a costly turnover in the second quarter. He was hit while attempting a pass, fumbled and saw it returned for the Steelers' third touchdown which gave them a 24-0 lead.

But after getting the ball back with 1:08 to play in the half, Mr. Sanchez showed exactly the confidence he'd talked about his parents imbuing him with this week. He completed three quick passes and ultimately got the Jets close enough for Nick Folk's 42-yard field goal. Then he came out firing in the second half.

The Jets had only one yard on the ground in the first half. On the first play of the second, Shonn Greene slashed down the left sideline for 23 yards. The Jets ran on the next two plays, Mr. Sanchez completed a tough third-down pass to Santonio Holmes and then, with the run game finally opening the play-action, he rolled out and hit Mr. Holmes with a gorgeously lofted 45-yard touchdown.

The next touchdown pass went to Jerricho Cotchery with 3:06 left, after the Jets had been stuffed on a fourth-and-goal at the Steelers' one-yard line—and after the Jets' defense pounced for a safety on Ben Roethlisberger, who mishandled a snap in the end zone.

Mr. Sanchez ultimately didn't have enough to propel his team to the Super Bowl. But the Jets beat the Colts' Peyton Manning and the Patriots' Tom Brady in the playoffs. That they didn't beat Mr. Roethlisberger was not because he was the superior of the two quarterbacks on Sunday.

Write to Aditi Kinkhabwala at aditi.kinkhabwala@wsj.com