Associated Press The San Francisco 49ers never have tasted defeat in a Super Bowl, going 5-0. It’s the most impressive mark for any franchise in the big game. Baltimore also is undefeated, with the Ravens winning their only appearance, in 2001. Someone will have the Super Bowl blahs for the first time after Sunday’s title game in the Superdome. The Ravens (13-6), who are 3½-point underdogs, are on one of those runs reminiscent of recent NFL champions. Indeed, the New York Giants reached the Super Bowl a year ago in a similar manner, winning a wild-card game at home, then two playoffs on the road. Ravens star linebackers Ray Lewis and Terrell Suggs are giving vintage performances following injury-shortened seasons. “I believe we have found a way to believe in each other, and nothing else matters,” said Lewis, who will retire after the game. Baltimore’s path to New Orleans led through New England, where the Ravens fell to the Patriots in last year’s AFC title game. But they outscored the Patriots 21-0 in the second half to earn their spot in the Super Bowl. San Francisco (13-4-1) also came up one win short a year ago, losing to the Giants for the NFC championship. That defeat has driven the 49ers just as much as the Ravens’ failure in 2011 lifted them.