Italian heavyweight prospect Guido Vianello brought down the hammer in a first-round knockout of Don Haynesworth to remain perfect.

Vianello floored Haynesworth flat on his back with an overhand right, and referee Jay Nady stopped the fight 2:16 into the opening frame at MGM Grand Conference Center.

The fight was the third of a five-bout card televised on ESPN and headlined by WBO 126-pound titleholder Shakur Stevenson’s debut at 130 pounds against Felix Caraballo in a non-title bout.

Clearly, pent-up quarantine aggression is resulting in KOs tonight. @vianello_guido is now 7-0 (7 KO) ?#StevensonCaraballo | LIVE NOW on ESPN pic.twitter.com/fpCxTjtUM8

— Top Rank Boxing (@trboxing) June 10, 2020

Vianello, who represented Italy at the 2016 Summer Olympics, not only remained undefeated but also continued his streak of knockouts. The 6-feet-6, 239-pound Vianello has knocked out all seven of his opponents.

Haynesworth (16-4-1, 14 KOs), 36, who tipped the scales at a plump 294½ pounds, has lost three of his last six fights, each by knockout.