What are your examples of 1 particular round permanently changing a fighter's path...

meldrick taylor vs chavez

 

Could there be a better example than wlad vs peter 1 round 5(i think)
Also khan vs maidana round 10
ortiz vs berto round 6
pacquiao vs marquez 2 round 3
taylor vs chavez round 12

 

I came in this thread thinking it would be about changing a fighter's path in a positive way, in which case I was going to say Khan vs Prescott round 1. It completeley changed his career in a huge way. He wouldn't where he is now without that loss.

As for one round having a negative impact, a modern example might be round 2 of Pac - Hatton. It was a highlight reel KO shown over and over and over again, and it was humiliating for Ricky. Far more so than a late stoppage or UD loss would have been. After this fight he quit boxing and took up the coke and hit the booze harder than ever before. Pretty big impact.

 

Camacho vs. Rosario round 5.

 

Lewis - Vitali Round 6

 

Pacquiao vs Cotto round 4

It didn't changed Cotto path but Floyd LOL

 

Froch-Taylor round 12, finally gave Froch belief that he could hang at world level, having looked like he was feeling sorry for himself all the way thru.

 

Pavlik/Taylor I: Round 3

 

A bit stretch but.. Wlad/Peter I, rd6. After two KD in fifth.

edit: already mentioned.

Tyson/Douglas, rd10.

Tarver/Jones 2, rd2.

 

For positive, JMM-Pac I round 2.

For negative, too many tragedies to mention unfortunately.

 

Camacho vs. Rosario. Rosario's punch made Hector turn from a possible ATG into a maybe Hall of fame fighter. It took some of Hector's commitment away. By commitment I mean he would not commit as much and just be defensive and win rounds and boring decisions. Before that he would dazzle.

 

Pac - Hatton, round 2 clearly takes this.

That KO devastated even Ricky's life outside of the ring.
Its devastation even reached his trainer, Mayweather Sr. (from walking like an @SS off the arena while his fighter was on the floor and the subsequent allegations and hatred that he hurled towards Pac that continues to this day.

Very tragic if you ask me.

 

Valuev vs. Haye - 12. If it weren't for that one big punch, the only meaningful thing Haye did in the entire fight, they could have never sold that bull**** decision.

Taylor vs. Abraham - 12. Caused Taylor to drop out of the S6, which I thought he had a semifinal shot locked up at the beginning.

Ray Mancini vs. Duk Koo Kim - 14 ...for obvious reasons for Kim, but it also changed Mancini's entire future.

Klitschko vs. Sanders - 2 Changed Wlad's entire game plan and views. He brought on Steward and after the setback with Brewster, developed into a beast.

 

Cotto vs pac round 3