How was he embarrassing against Haye? He came to fight, came forward and looked to put it on Haye. Yeah he came up short, but as we've seen since he's bounced back.
Chisora gave Vitali his best fight since Lewis and comfortably beat Helenius. He's better than both those performances now.
That remains yet to be seen, but I do believe he is a big name big occasion fighter. He seems to find it hard to get motivated properly for when he isn't the underdog.