ST. LOUIS - Nothing comes easy for the Carolina Panthers - not even their biggest victory.

After blowing an 11-point lead in the final 2:39, the Panthers beat the St. Louis Rams 29-23 in double overtime Saturday on Steve Smith's 69-yard touchdown reception.

In one of the wildest, most thrilling finishes in NFL history, Carolina advanced to the NFC championship game against either Philadelphia or Green Bay.

But the Panthers, in the playoffs for only the second time, made it plenty difficult in a back-and-forth game that featured momentum swings with just about every possession in the last 30 minutes. Of course, Carolina has won 10 of its 13 games decided by six points or fewer this season.

After St. Louis rallied to tie the game in regulation on a touchdown run by Marshall Faulk, a 2-point conversion, an onside kick and a 33-yard field goal by Jeff Wilkins, Carolina nearly won it on the first possession of overtime.

The Panthers took the overtime kickoff and moved to the Rams 22 on Jermaine Wiggins' 21-yard reception. John Kasay made a 40-yard field goal, but the Panthers were called for delay of game. The offense came back for two runs and Kasay, the last original Panther, was wide right from 45 yards.

Jeff Wilkins was short on a 53-yard attempt for St. Louis, and the Rams then forced a punt. With St. Louis moving the ball, rookie Ricky Manning Jr., wrestled a pass away from Torry Holt for an interception at the Carolina 38.

Three plays later, on the first snap of the second OT, Smith split a zone, beating safety Jason Sehorn and carrying Jake Delhomme's pass into the end zone to win the fifth-longest game ever.

It also snapped a 14-game home winning streak for the Rams and was their first postseason loss in the Edward Jones Dome, which fell silent as Smith scooted to the end zone.

Delhomme, growing more comfortable with each playoff outing, was 16-for-26 for 290 yards and the winning pass under the most difficult of circumstances.

Marc Bulger was 27-for-46 for 332 yards, but had three interceptions.