He lost control of his legs as a consequence of the punch on his head. With a 100% injury-free knee he would be able to stay on his feet (there were 3 seconds remaining in the first round) but he was definitely hurt and wobbled slightly by that punch and regarding that fact he had no chance of winning the fight if it went on.
Haye went down from a temple shot to Mock, and I think Mormeck was a temple shot, but I haven't seem that fight for ages so I might be wrong. Brits have glass temples
Solis was knocked down by a punch to his glass temple. Any other injuries were the result of getting his equilibrium knocked out of whack & his **** poor condition.
Vitali hit him so hard that the shockwave the punch sent was so strong that Solis knee tore on impact