Topline. Texas furniture kingpin Jim McIngvale better known as Mattress Mack  won $75 million on Saturday after his bet that the Houston Astros would win the World Series paid off, taking home what is believed to be the largest payout in legal sports betting history.

The largest single jackpot ever won in a casino was $39.7 million on the Megabucks slot machine at the Excalibur Hotel & Casino in Las Vegas, Nevada, on March 12, 2003. The winner was a 25-year-old software engineer from Los Angeles who remained anonymous.