Roger Federer is tennis' acknowledged grand slam king. With the all-time records for grand slam titles (16), consecutive semifinal appearances (23), and consecutive quarterfinal appearances (32, and counting), its easy to overlook the matches that might have undone these streaks and changed his legacy. These are the seven matches before the quarterfinals that could have done just that.
Tommy Haas Australian Open 2006: 6-4, 6-0, 3-6, 4-6, 6-2
Federer enjoyed a career-defining season in 2006, compiling an astounding 92-5 record, and winning 12 titles. Leading into the first grand slam of the season in Melbourne he had won Doha, and it looked likely that he would claim the Australian Open crown a second time.
Easing through the first three rounds he faced a German four years his elder, and once a world number two, Tommy Haas, who had a glorious single-handed backhand. Federer eased through the first two sets of the match, and it looked like a routine win was on the cards. Haas had beaten him the last time at Rod Laver Arena, in a heartbreaker in 2002, and it seemed Federer would quell the demons at last.
But the veteran was wily, and he contrived to break Federer in both the third and fourth sets to stretch it to an unlikely fifth. In the decider, however, Federer stepped up in class, and with some sublime hitting broke Haas decisively, twice, to seal the encounter.
Federer would go on to win the Australian Open, receiving the trophy from Rod Laver, to set the tone to a historic season where he sought to equal the Australian's feat of a calendar grand slam.
It was a close shave, and the quest for glory could have ended there that night. But Federer in winning advanced to the peak of his powers, and his victory heralded his dominance for a year and a half, the amount of time which would pass before he played another five-set grand slam match (at Wimbledon tin 2007).