For the first time since his amateur debut, Biaggio Ali Walsh -- the grandson of the legendary Muhammad Ali -- tastes defeat, as Chicago native Ronnie Gibbs pulled off the unbelievable upset with a submission during the early card of PFL Chicago.

Ali Walsh entered this fight as a -1100 favorite per DraftKings, while Gibbs was a +950 underdog.

Gibbs, however, stole the momentum in the second round. Gibbs got a takedown late in the first and managed to get the fight back to the ground in the second, landing some strong ground-and-pound before an arm-triangle put Ali Walsh unconscious to secure the massive upset.

Ronnie Gibbs Scores Massive Upset Over Biaggio Ali Walsh At PFL Chicago

Ali Walsh went 6-1 as an amateur, with most of his appearances coming with the PFL, before turning pro last year, winning two fights.

Gibbs made his pro debut in March after his own 6-1 amateur stint, defeating Luis Unzueta.