I don't think it really fits your criteria but Ramirez performance against Arguello is somewhat of an example.
Ramirez always had good Boxing skills and defense but a lot of people only really talk about the Whitaker fights and the Camacho fight to a lesser extent where he was all out aggresion.
He was an aggressive fighter most of the time but against Arguello it was a display of great Boxing skills off the back foot and his underrated defense. People don't realise that Ramirez was actually very good defensively, slipping punches etc. The fight against Arguello was the performance of his career, shame he didn't get the decision, he deserved it IMO. I think that's possibly the only fight of his career where he boxed to a tee for the full fight, didn't get off his gameplan and go to war. He knew he couldn't with Arguello
That's why. But that's why I used it as an example. He didn't really "Change his style" though because Ramirez was always skilled like that. But rarely did he fight like that, for a whole fight.
Ramirez is so underrated these days. I remember someone I was talking to on here was comparing him to Harry Simon. Harry Simon!