Holzhauer debuted at the World Series of Poker in 2019. In his first event, he finished 454th out of approximately 1,800 contestants and did not win any prize money (he would have needed to finish at 281st or higher to win any prize money). His second event was a tag-team match in which he partnered with Mike Sexton. He ultimately was knocked out as a solo contestant in round 17 of the tournament, with his most notable prize win being a $600 profit for finishing 92nd out of 1,867 on a game.