Andy Ruiz Jr. was forced to do it the hard way as he returned to winning ways against Chris Arreola.
The "Mexican Destroyer", who had Saul 'Canelo' Alvarez's trainer Eddy Reynoso in the corner, was dealt a crisis in the second round as his knee hit the canvas.
Returning for the first time since his defeat to Anthony Joshua in their Saudi Arabia rematch, Ruiz survived rounds two and three to rally back to a points victory.
All three judges' scorecards had it in favour of Mexico's first heavyweight world champion. They read 117-110, 118-109, 118-109.
"Chris is a veteran and a hard puncher," said Ruiz Jr, who is open to facing Deontay Wilder next.
"We did what we had to do tonight. We got the victory that we wanted. I was at my lowest point and now I have to climb the ladder again.
"I'm thankful for the victory and I'm ready to move on to the next.
"He got me with a good clean right hand in the second round. I was too overconfident and dropped my hand a bit. Hats off to him.
"We just kept pushing and pushing. I switched up and started focusing on counter-punching and working the body.
"I felt a little rust and I know other fighters can relate to that. If he wants to run it back, we'll run it back with him."
Lara makes light work, Ramos family run riot
Confirming some bad match-making, Erislandy Lara won the secondary WBA middleweight title with a ruthless knockout of Thomas Lamanna in the opening round.
Lara, who could have easily beat Canelo on another night of scorecards in 2014, may face Ryota Murata for the full version of the belt.
Elsewhere, Abel Ramos delivered a shock upset win by overcoming Omar Figueroa Jr.
Ramos worked out his American opponent and the onslaught saw Figueroa, 31, unable to return in round seven after spitting blood in his corner.
Ramos, a former welterweight world challenger, celebrated alongside his cousin later that night after Jesus, 20, also won on the undercard with victory over Javier Molina.
Eduardo Ramirez also had his hand raised. He knocked out Issac Avelar inside three rounds to pick up the WBA interim featherweight title.