Reed and Lewis each had interceptions that turned into touchdowns in the fourth quarter, Joe Flacco threw for 301 yards and a TD, and the Ravens overcame St. Pierre's 88-yard touchdown pass to beat the stubborn Panthers 37-13 on Sunday.
"It was only a matter of time," said Reed, who collected his 50th interception and then pitched it to Dawan Landry for a TD and a 30-13 lead. "We knew Brian St. Pierre was only with the team for this week. We knew they would be very cautious with the ball and play to their defense, which they did and hung around.
"It was just a matter of time for guys to be in the places they needed to be."
The Ravens (7-3) recovered after a disheartening loss to Atlanta 10 days earlier by finally rattling Carolina's inexperienced quarterback. Reed picked off St. Pierre, ran 19 yards, then pitched it to Landry, who went the remaining 23 yards for a touchdown with 4:59 left.
On the next play, Lewis got his 30th interception, returning St. Pierre's pass 24 yards for a score and Baltimore kept pace with victorious Pittsburgh atop the division.
"It doesn't get any better," Lewis said. "We came out and got the victory we were supposed to get."
He wiped out any chance of an improbable victory for St. Pierre, signed by Carolina (1-9) a little over a week ago. He threw his long TD pass to David Gettis early in the fourth quarter to get the Panthers within a touchdown.
"He just rolled out of bed and threw 80-yard bombs," receiver Steve Smith said.
T.J. Houshmandzadeh's 56-yard touchdown catch on the Ravens' second play from scrimmage was the 600th reception of his career and the 51st TD pass for Flacco, tying him with Vinny Testaverde for the franchise lead.
Derrick Mason became the 13th player in NFL history with 900 career catches in the third quarter.
And they needed it all to fend off the Panthers.
"You just get tired of the little victories being your only ones," left tackle Jordan Gross said.
Mike Goodson rushed for 120 yards, his second straight 100-yard game after Carolina's top three running backs were sidelined with injuries. St. Pierre was 13 of 28 for 173 yards, but his two late interceptions sent the Panthers to their fourth straight loss.
"Even though I haven't played a lot in this league, I have a lot of pride doing a job and doing my job right," St. Pierre said. "I wish I did it a little better today."
St. Pierre, who just over a week ago was a stay-at-home dad, hadn't been in the NFL since the end of last season. Embattled coach John Fox gave him the starting job over rookie Tony Pike after Matt Moore (shoulder) and Jimmy Clausen (concussion) were sidelined in the past two weeks.
The 30-year-old St. Pierre, who played at Boston College and was a 2003 fifth-round pick by Pittsburgh, had thrown five passes in eight years as mostly a No. 3 QB with the Steelers, Ravens and Cardinals.
He spent the first three quarters throwing only short swing passes and screens -- even on third-and-long -- and the Panthers had 39 yards passing entering the fourth quarter.
When he finally got a chance to air it out, it gave the Panthers brief hope.
St. Pierre 's long spiral down the left sideline was caught in stride by the rookie Gettis, who bolted for a touchdown and the second-longest play in franchise history. It cut Baltimore's once 17-point lead to 20-13 with 14:44 left.
To put that into perspective, that pass was more than seven times the yards passing St. Pierre had in his career (12 yards) coming into the game. Reed and Lewis soon ended Carolina's chances, much to the delight of a crowd that included thousands of Baltimore fans.
"I didn't want to be the reason we lost," St. Pierre said. "Unfortunately, I was definitely part of it."
As the Panthers moved ahead of victorious Buffalo in the race for the No. 1 draft pick, the Ravens close with four of six at home.
"I don't think we played as great as we wanted to at times and we're going to have to look at that," said Flacco, who was 24 of 33 with no interceptions, "But it was good to come down here and get a win."
Tony Moll started for Baltimore at right guard for Chris Chester, who has been hospitalized with a high fever following a skin infection. "He's probably going to be [out] a week or two until the thing calms down," coach John Harbaugh said. ... The Ravens may have finally found a reliable return man. David Reed had an 84-yard return that set up a field goal. ... Cundiff, who came in with an NFL-high 25 touchbacks, had four more. ... Panthers S Jordan Pugh left with a right hamstring injury.