During the 1943 season, Culberson played in 81 games for Boston, hitting .272 and stealing 14 bases; third best on the team in each of those categories. On July 3, he hit for the cycle against the Cleveland Indians. Batting lead off, he hit a single in the 1st inning, a double in the 3rd inning, a triple in the 6th inning, and a home run (inside-the-park) in the 8th inning. By collecting the hits in that order it was a rare "natural" cycle, the fifth in MLB history. In 1944, his average fell to .238 playing in 75 games, then in 1945 he raised his average to .275 while appearing in 97 games. He played through the war years due to a trick knee condition that rendered him unfit for military duty, and also sidelined him at times.