Tony Conigliaro began his comeback in professional baseball yesterday by slamming a two-run homer and scoring the winning run for the Boston Red Sox in a 12-inning 5-4 victory over the Baltimore Orioles. The game was the season opener for both clubs.

Oriole Mark Belanger sent the game into extra innings with a triple in the eight that tied the score at 2-2. Conigliaro, returning to baseball after a serious eye injury in 1967, hit his four-bagger with a man aboard in the tenth. Baltimore's Frank Robinson kept his team in the game with a two-run homer with two out in the bottom half of the inning.

Tony Scores Again

Two innings later, the Red Sox loaded the bases on a walk to Conigliaro, a single by George Scott, and a walk to Rico Petrocelli. Pinchhitter Dalton Jones hit a sacrifice fly one out later to score Conigliaro from third.

Jim Lonborg, hurt in a skiing accident last year, retired the first seven Baltimore batters before Belanger homered in the third. Manager Dick Williams removed Lonborg because he complained of shoulder pains of the type that bothered him during spring training. Reliever Bill Landis was the eventual winning pitcher.