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Andrew Luck doesn't expect this whole NFL thing to be easy.

Still, there have been times during the rookie quarterback's first two games for the Indianapolis Colts that he certainly made it look that way.

Showcasing the mental toughness — not to mention the breathtaking skills — that made him the top pick in the draft, Luck won over the Pittsburgh Steelers in a 26-24 preseason loss on Sunday night.

Luck shook off his first two interceptions as a pro to pass for 175 yards and run for a touchdown to erase an early 14-point deficit and exit with the lead.

"He's a tough kid," Pittsburgh defensive end Brett Keisel said. "He's a good quarterback. I think he's going to play a long time. (Colts offensive coordinator) Bruce (Arians) is, I'm sure, a happy man."

Hard to blame him.

Luck was simply dazzling in his preseason debut last week, shredding the St. Louis Rams for a pair of touchdowns. He knew the going would be considerably tougher against the Steelers (No. 7 in the AP Pro32), even if Pittsburgh (1-1) was playing without injured defensive stars James Harrison and Casey Hampton.

There were a couple of moments Luck looked overwhelmed, particularly when Steelers cornerback Ike Taylor stepped in front of an underthrown pass and raced 50 yards for a touchdown.

Standing on the sideline fuming, Luck collected himself. It's what he does.

"You've got a chance to go out there again, so you kind of flush it and focus on the next play," Luck said. "You're thinking so much with all the play calls that it's easy to forget about good or bad what happened earlier."

Luck bounced back with a sublime quarter in which he refused to get rattled against the defense that finished No. 1 in the league last fall.

Using his mobility to step away from pressure and his vision to find open receivers, Luck didn't look like a guy who won't make his first NFL regular-season start for another three weeks.

"(Luck) was able to come back and put it behind him just like he always has," Indianapolis coach Chuck Pagano said. "We saw the same thing in college. He's able to bring his team back from behind so it was nothing surprising to us to see him come back and put those kind of drives together."

The Steelers aren't undergoing the kind of drastic makeover the Colts (No. 32) are enduring. Still, they have issues, namely getting used to new offensive coordinator Todd Haley's complex scheme.

The results so far are mixed.

Ben Roethlisberger completed 7 of 8 passes during his one drive of work in the opener against Philadelphia last week, all of them quick hitters. His first pass Sunday night ended up in the hands of Indianapolis' Antoine Bethea.

Antonio Brown and Roethlisberger atoned the next time the Steelers had the ball, with Brown doing most of the work. He hauled in an 18-yard pass from Roethlisberger on third-and-11 to extend the drive then put together a highlight-reel 57 yard catch-and-run for a touchdown.

The play was all Brown. He took a screen pass from Roethlisberger, cut to the middle and used some great downfield blocking by running back Baron Batch to get to the end zone. Brown — who has become Roethlisberger's favorite target with Mike Wallace in the midst of a holdout — added some style points by doing a flip as he crossed the goal line.

"It'd give it an 8.5," Brown said about the somersault. "I didn't stick the landing."

And the Steelers didn't stick with it. The play accounted for more than half of the 112 yards of offense Pittsburgh generated when Roethlisberger was in the huddle. Roethlisberger completed 5 of 9 passes for 81 yards and the touchdown to Brown.

"We're making a little bit of progress," Roethlisberger said. "I still think we're leaving a lot out there. We're not playing as good as we could or should, but we're making progress."

So are the Colts.

On the verge of getting blown out, the Colts responded behind their new leader. Luck led a 10-play, 80-yard drive after Taylor's pick and Donald Brown got Indianapolis on the board with a 1-yard plunge.

Luck had it going on Indianapolis' next possession before being undone by a turnover. He found rookie wide receiver T.Y. Hilton in stride down the middle only to have the wide-open Hilton throw the ball up in the air. Pittsburgh's Cortez Allen ran underneath it to thwart the drive, but it hardly slowed the Colts.

Indianapolis tied it at 14 when Luck deftly slid into the end zone on fourth-and-goal from the 1, ending a drive in which Luck completed all five of his passes.

Luck got one more chance just before the half, and he made it count. Working exclusively out of the shotgun, Luck led the Colts 31 yards in five plays, giving Adam Vinatieri just enough time — and room — to sneak a kick between the uprights at the halftime gun.

NOTES: Colts DE Robert Mathis left the game in the first quarter with a shoulder strain and did not return. Indianapolis WR Austin Collie underwent a concussion test after taking a blow to the head from Pittsburgh linebacker Larry Foote. ... The Steelers travel to Buffalo on Saturday night while the Colts visit Washington. ... Harrison, Hampton, running backs Isaac Redman and Rashard Mendenhall and linebacker Jason Worilds did not dress for the Steelers. ... Indianapolis backup QB Drew Stanton completed 4 of 13 passes for 69 yards and a touchdown.