If you already penciled in the Miami Heat as the Boston Celtics' first-round playoff opponent before Tuesday night, you're not alone.

Prior to Miami's NBA play-in tournament matchup with the 41-41 Atlanta Hawks, TNT analyst Charles Barkley confidently picked the Heat to win easily -- and was willing to back it up with cash.

"They're gonna beat the Hawks. Come on, the Hawks stink," Barkley told co-host Shaquille O'Neal, before saying he'd be willing to bet "a billion dollars" on a Heat win.

Fast forward to a few hours later after the Hawks pulled off a 116-105 upset victory that punched their ticket to Round 1 to face the Celtics beginning Saturday at 3:30 p.m. ET. Shaq made sure to remind Chuck of his pregame bet.