Peter Diana, Post-Gazette Steelers quarterback Ben Roethlisberger drops back to pass against the Detroit Lions at Ford Field in Detroit last night. Click photo for larger image. More Steelers News: Steelers Notebook: Staley gets starting nod over Bettis in opener

DETROIT -- The Ben Roethlisberger era did not necessarily begin last night, but the Steelers rookie quarterback did experience a baptism by fire ... and the flare belonged to him.

Roethlisberger made his pro debut and gave the Steelers their first official snapshot of what he has to offer. The only quarterback drafted by the Steelers on the first round in the past 24 years, he made a good first impression in a 27-21 loss to the Detroit Lions in an exhibition opener at Ford Field.

Replacing starter Tommy Maddox early in the second quarter, Roethlisberger threw his first pro touchdown pass -- it went for 7 yards -- to Antwaan Randle El. Roethlisberger then walked off the field without celebrating, as if he had done that sort of thing a million times. He made good decisions, looked poised and, for the most part, was on target with his passes.

Roethlisberger completed 8 of 13 passes for 84 yards. Two other passes covered 32 yards but were nullified by penalties.

His passer rating for the game was 105.9 and afterward Steelers coach Bill Cowher officially proclaimed him the No. 2 quarterback.

"I thought Ben did a lot of good things," Cowher said. "I liked his presence in the pocket. Obviously the athleticism he displayed in camp was very evident out there on the field. I thought he made good decisions, threw the ball very accurately with good touch. I thought he had a good [game]."

Not to be outdone, second-year pro Brian St. Pierre made a statement of his own. He proved that just because veteran backup Charlie Batch is out for the season with a knee injury does not mean the Steelers do not have a reliable option at No. 2 or No. 3 behind Maddox.

St. Pierre replaced Roethlisberger midway through the third quarter, took his first snap and threw a 26-yard touchdown pass to Freddie Milons. St. Pierre directed the Steelers to another touchdown -- Dante Brown's 22-yard run -- in the fourth quarter after a 59-yard kickoff return by rookie Ricardo Colclough.

St. Pierre nearly won the game at the end, but his last pass fell incomplete in the Lions' end zone. St. Pierre was 4 of 8 for 88 yards.

Cowher said he has enough confidence in his remaining quarterbacks that he sees no need to sign anyone else.

"I can't foresee a need at this point," said Cowher, who also praised the play of starter Tommy Maddox (4 of 5, 52 yards) and the rest of the first-team offense.

Duce Staley started ahead of Jerome Bettis at running back and rushed for 45 yards on 11 carries. Bettis replaced him in the second quarter and carried five times for five yards.

Staley looked good on the first drive with 40 yards on nine carries. But on second down at the Lions' 6, cornerback Rod Babers popped Staley with a shoulder and the ball skidded loose toward the end zone. Guard Alan Faneca appeared to cover it for a touchdown but officials ruled he did not have possession before he rolled through the endline.

"I thought we did a nice job," Cowher said of the first team. "There wasn't a whole lot of negatives. It was pretty good for the first game."

Staley's fumble gave the ball to the Lions at the 20 and they moved 80 yards for a touchdown to take a 7-0 lead.

Quarterback Joey Harrington rolled to his right from the 1 on third down under pressure from linebacker James Farrior. He found tight end Casey Fitzsimmons, who had broken away from linebacker Kendrell Bell, in the back middle of the end zone.

Roethlisberger entered his first professional game with 11:36 left in the second quarter. Cowher kept the starting offensive line in the game to give Roethlisberger some extra comfort. Roethlisberger completed his first pass on a bootleg to the right. Tight end Jay Riemersma catch the ball for 15 yards.

"Riemersma was wide open and I didn't want to miss him," Roethlisberger said.

Roethlisberger completed another pass to Randle El for 14 yards on his second series. That drive appeared to end on fourth-and five from the 27 as the Steelers lined up in a punt formation. However, Troy Polamalu took a short snap and ran 65 yards, breaking one tackle and eluding two others. He fumbled as tried to lateral the ball, but teammate Matt Cushing recovered at the Lions 9.

That gave Roethlisberger another chance and on second down he lofted a pass that Randle El leaped high and caught for a 7-yard gain and a touchdown. That tied the score, 7-7, with 3:24 left in the first half.

"It's great to get that first touchdown out of the way but it was a terrible throw," Roethlisberger said. "When I came off the field Coach Cowher said 'I didn't think we were in duck season right now.' But you put it up to your playmakers and Antwaan Randle El will make a play every down."

The Lions led 10-7 at halftime after Jason Hanson's 46-yard field goal on a drive led by quarterback Mike McMahon, a North Allegheny High School graduate and the Lions' top backup.

Detroit extended its lead to 17-7 early in the second half on Olandis Gary's 1-yard run but McMahon was the star of that series. He completed a 43-yard pass on third down to former Penn State standout Eddie Drummond. that landed in and bounced out of the hands of safety Ainsley Battles. Then, from the Steelers 12, McMahon eluded linebacker Adrian Ross in the backfield and scrambled up the middle to the 1.

Former Lions cornerback Terry Fair intercepted McMahon in the third quarter and St. Pierre converted the turnover into points. He replaced Roethlisberger, took his first snap and delivered a 26-yard touchdown pass to Milons to bring the Steelers within three, 17-14.

Rookie Chris Snyder's 50-yard field goal early in the fourth quarter boosted Detroit's lead to 20-14.

Steelers running back Dante Brown then fumbled at the Lions' 21 and Detroit converted that turnover into a 7-yard touchdown run by Avon Cobourne and a 27-14 lead with 13:03 left.

Colclough followed with a 59-yard kickoff return for the Steelers and Brown made up for his previous gaffe when he ran 22 yards untouched for a score that brought the Steelers back within six points.