June 3, 2003, Tampa Bay Devil Rays at Chicago Cubs
Sammy Sosa uses a corked bat in a game against the Devil Rays and is ejected and suspended for 8 games. He appealed his suspension, and it was reduced to 7 games. The MLB confiscated 77 other Sosa bats and x-rayed them, and no cork was found in any of them.
For context: At the time of the incident, Sammy had just returned from the disabled list after having missed 17 games. This was his fourth game back from injury, and in the first two games back, his timing was way behind his normal timing after all the time off. In his first game back, on May 30, he went 0 for 4 with 3 strikeouts, and in his second game back, on May 31, he went 1 for 7 with 5 strikeouts.