Though he had a mediocre career record, Larsen was immortalized by his World Series perfect game of October 8, 1956. He had gone 11-5 for the Yankees that year and, after being knocked out in the second inning of Game Two, started Game Five. He set down 27 Dodgers in a row, outdueling Sal Maglie and winning 2-0 for the first no-hitter in Series history. The last batter Larsen faced was Dale Mitchell, who was declared out by umpire Babe Pinelli on a called third strike. Mitchell and others, including Mickey Mantle in centerfield, thought the ball a bit outside, but mayhem had erupted and catcher Yogi Berra had jumped into Larsen's arms before Mitchell could argue.

Before joining the Yankees, Larsen had a 3-21 record for the 1954 Orioles to lead the AL in losses. But two of his wins came against New York, who took him as part of an 18-player deal that winter. One early morning in spring training of 1956, Larsen, who had a reputation as a partier, crashed his car into a telephone pole, prompting manager Casey Stengel to say, "He was probably mailing a letter." But he was a capable pitcher who, like Yankee teammate Bob Turley, adopted a no-windup delivery. His 11 wins in 1956 were his season high. He went 1-10 with the A's in 1960 and bounced around before receiving his last ML chance with the Cubs in 1967. He was the last active former St. Louis Brown. A lifetime .242 batter, he had 14 career home runs and was used 66 times as a pinch hitter.