Mats Wilander said on Eurosport that the second set of the Australian Open semifinal between Federer and Roddick was the best set of tennis he had ever seen by a single player, and at the end, he said it was the best match he had ever seen anyone play: 6-4, 6-0, 6-2, with Federer winning 15 of the last 17 games after being down (on serve) at 3-4 in the first set.
Well, I once saw a set at least the equal of Federer's second-set dismantling of Roddick (24 points to 6!): the fourth and final set of the French Open final between Gustavo Kuerten and Alex Corretja in 2001. Kuerten won the first 23 points of the set to go up 5-0, 40-0. Then a funny thing happened on match point: Corretja won three straight points to get back to deuce before Kuerten then won the last two to win the match. Point total for the set: 25-3. For the sake of completeness: the score of the match in the end was 6-7(0) 7-5 6-2 6-0. (I had forgotten that Kuerten lost the first-set tiebreak at love!)
And for the sake of rubbing it in for Roddick fans: Federer 13, Roddick 1. :-)