PITTSBURGH - The opening act of the Ravens' Kyle Boller saga turned into a horror show, and the first steps of a much-hyped defense transformed into a comedy of errors.

Lacking consistency at quarterback and focus in the secondary, the Ravens' coming-out party was crashed unmercifully by the Pittsburgh Steelers in a 34-15 loss before 63,157 at Heinz Field yesterday.

After touting themselves as playoff contenders, the Ravens didn't seem like they were in the same league as the Steelers, much less the same division. The 19-point loss to their AFC North rival represented the worst season-opening loss in the franchise's eight-year history.

"This was very disappointing," Ravens coach Brian Billick said. "We said this was a measuring stick for us to see how far we've come from last year. Obviously, we still have a long way to go."

Boller's first NFL start was predictable - which was predictably erratic for a rookie quarterback.

The 19th overall pick in the NFL draft, Boller misfired on three of his first four throws in a rough initiation against the pressure-packed Pittsburgh defense.

His first throw sailed over running back Jamal Lewis' head. His third was intercepted by linebacker Kendrell Bell. And his fourth was nearly picked off by cornerback Chad Scott, who let the deep pass slip through his arms.

His inexperience had the biggest effect on third downs, where the Ravens failed to convert in 11 of 16 tries.

"I'd be lying if I didn't say I missed some throws I've got to make," said Boller, who finished 22-for-43 for 152 yards and a quarterback rating of 57.5. "There's definitely times when we could have moved the chains if I wouldn't have made a mistake. It was definitely a lot faster than the preseason. I could tell that right away."

The Ravens produced one first down in the first quarter. They didn't cross midfield until 8:35 left in the first half.

By the time they cracked the Steelers' 20-yard line, the Ravens were behind 27-0 late in the third quarter.

"I don't think that [lack of productivity] has anything to do with Kyle," receiver Travis Taylor said. "The offense is made of 11 people. I think with all us working on the same page, we can make up for what he doesn't know or doesn't have."

Boller's first mistake marked his biggest.

Staring down Todd Heap, Boller was intercepted by Bell, who crossed in front of the Ravens tight end and returned the pass 42 yards to the Ravens' 28-yard line. Although the Steelers only converted a field goal out of it, the turnover affected the game beyond three points.

"That set the tone," Steelers coach Bill Cowher said.

Still, the Ravens trailed only 6-0 late into the second quarter because of their defense. But after playing nearly 18 of the first 27 minutes, the defense began a string of lapses.

The Steelers marched 90 yards on eight plays, reaching the end zone on a 4-yard pass from quarterback Tommy Maddox to Hines Ward. The length-of-the-field drive was set up by a 47-yard pass to Plaxico Burress, who raced behind safety Will Demps and cornerback Corey Fuller in a coverage breakdown.

"I think we were playing well right up until that play," Fuller said. "They got that [47-yard] play, and the next thing you know, they come up with a touchdown right after that. Then the snowball was really coming down full speed."

The 13-0 halftime deficit became a 27-0 hole as Maddox threw touchdown passes of 20 and 28 yards in the third quarter.