Vitali Klitschko in many boxing experts opinions was beating Lennox Lewis before their fight was stopped due to a nasty cut on the Ukranian, handing Lennox the win. In reality Lennox Lewis was nearly retired and he wasn’t near his peak at that stage. That was Vitali’s breakout fight and he left many fans impressed after his performance.
I think a prime Lennox Lewis would beat both Vitali and Wladimir. I expect a prime Wladimir would have had the best chance to outpoint Lennox Lewis. The brothers are different, Vitali was overall stronger and had a better chin. Wladimir was the better boxer and mover, his power was also awesome, however his chin has let him down in the past. I think if all three fighters were in their prime, I would favour Lewis to beat them both. But a prime Wladimir would have a great chance of winning, considering Vitali was close to beating Lewis also.