Del Potro is a player who has often performed a real GOAT big tournament. I can not think of a player name that can beat the Argentine on hardcourt, when he plays at the top of the form. What were the players that even if only in a big tournament (not just a match) they played a GOAT tennis but in their career they did not win much. Wawinka and Ivanisevic for example. Panatta? Maybe. Does any name come to mind?