On Opening Day, April 5, 2010, Molina connected for a grand slam, becoming just the third Cardinals player to hit an Opening Day grand slam, following Mark McGwire and Scott Rolen. On April 17, he caught all 20 innings of a game against the Mets. Molina turned in a productive April, driving in 15 runners, the most for a Cardinals catcher in the month of April since Ted Simmons drove in 20 in 1977. He also continued his productivity with the bases loaded that month, collecting four hits and 11 RBIs in five at bats.