Backup quarterback Stoney Case gave the Baltimore Ravens an opportunity to win, but a defensive blunder cost them a chance at their first victory of the season.

Case took over for an ineffective Scott Mitchell and completed his first NFL touchdown pass to tie the score late in the fourth quarter. Pittsburgh needed barely more than a minute to march down the field and kick a 36-yard field goal as time expired to beat the Ravens, 23-20, today at PSINet Stadium.

Let the quarterback controversy begin.

"We were trying to make some things happen," Baltimore Coach Brian Billick said. "We needed to get somebody in there who could move around. That's not particularly Scott's strength. Things weren't happening for him. Things weren't happening around him."

But Billick declined to name Case the starter against Cleveland on Sunday.

"I'll let you know," he said.

Many of the 68,965 fans who booed Mitchell off the field cheered wildly when Case entered the game with 9 minutes 18 seconds remaining in the third quarter. Mitchell completed 7 of 16 passes for 48 yards and threw two interceptions before leaving the game.

Case's debut was less than impressive. In his first series, he threw two incomplete passes and was called for a delay of game before the Ravens (0-2) had to punt.

His next drive lasted one play. Case was sacked by linebacker Carlos Emmons and fumbled, setting up a 32-yard field goal by Kris Brown to give Pittsburgh a 17-10 lead. "I'm real disappointed," Case said. "It took me too long to get going. . . . I was thinking too much out there."

Case began to find his rhythm on his fifth series. The first play of the drive he connected with Qadry Ismail for a 20-yard pass. On fourth and one, Case found Justin Armour on the left sideline for a 17-yard pass play. The Ravens had to settle for a 28-yard field goal when Case's pass to Ismail was tipped out of his hands in the end zone.

On Baltimore's next possession, Case put together a six-play drive that covered 72 yards. It resulted in a 19-yard touchdown pass to Ismail that tied the score at 20 with 1:22 remaining.

"It was definitely exciting," said Case, who completed 7 of 15 passes for 130 yards and one touchdown. "This is my dream--to be an NFL quarterback, to be on the field making plays."

However, Baltimore's defense, flustered by the 37-yard kickoff return by Will Blackwell to the 50-yard line, failed to put enough players on the field for the Steelers' first offensive play. (Earlier in the game, on two punt returns, the Ravens failed to field 11 men.) With nine Ravens on defense, Kordell Stewart completed a 12-yard pass to Troy Edwards for a first down.

"I don't know exactly what happened," defensive tackle Tony Siragusa said. "There was a lot of confusion. Guys were upset they ran the ball back on our territory."

The Ravens were out of timeouts at that point and could not have taken one to set the defense.

"Some different packages" were called, defensive tackle Larry Webster said. "Guys didn't remember them."

Running back Errict Rhett, starting for the injured Priest Holmes (knee), scored Baltimore's first touchdown with 1:39 left in the first quarter. Rhett bowled his way into the end zone from two yards out to tie the score at 7. The Ravens added a 45-yard field goal by Matt Stover to trail the Steelers 14-10 at the half.

Rhett, who fell out of favor with former Ravens Coach Ted Marchibroda last season, had his first 100-yard rushing game since Dec. 10, 1995. He carried the ball 22 times for 101 yards.

"I think I've gotten better like wine gets better with time," Rhett said. "I don't think nothing's changed. . . . I'm 10 times better now than I was back in the beginning of my years playing football."