The longest Opening Day game in major league history was played on April 5, 2012 in a game between the Cleveland Indians and Toronto Blue Jays. The game, played at Cleveland's Progressive Field, ended with the beating the - in innings.â†µ
The Indians and Jays are currently playing the longest extra-innings game in Opening Day history. The above passage from Wikipedia is what came up in a Google search for "longest extra-innings game in Opening Day history."â†µ
The Internet freaks me out.