UPSET: Ruiz Jr defeats Anthony Joshua to become first Mexican world heavyweight champion

Andy Ruiz Jr. stunned Anthony Joshua on his US debut with a “TKO” in the seventh round, becomes Mexico’s first ever world heavyweight champion.

Ruiz walks away from Madison Square Garden with all of Joshua’s titles — including the WBA, WBO and IBF crowns.

Ruiz Jr took the place of Jarrel Miller, AJ’s original challenger who tested positive for three different performance-enhancing drugs in three separate tests shortly after the fight was announced.

One of the biggest upsets heavyweight boxing has ever seen after Buster Douglas Vs Mike Tyson and James Braddock Vs Max Baer in the history of the sport.

The Mexican came off the floor in the third round to drop Joshua twice before the end of the frame.

Then the 29-year-old Californian sent Joshua to the canvas for a third time in the seventh round before referee Mike Griffin put a stop to the proceedings at the 1:27 mark.

“Boxing’s a tough sport,” Joshua said after his first career defeat.

“I’ve trained hard, I’ve trained dedicated and I just got beat by a good fighter tonight.

“This is all part of the journey.”

Ruiz Jr said it was dream come true after he became heavyweight champion of the world.

“This is what I’ve been dreaming about, what I’ve been working hard for, I can’t believe I just made my dreams come true.

“I just want to thank God for giving me this victory, without him this wouldn’t have been possible.

“I just felt so good. The sky’s the limit baby!”

Eddie Hearn, AJ’s promoter says a rematch is on the cards.

“We’ll make the rematch in the UK in November/December, but tonight is all about Andy Ruiz,” Hearn said.