#4. 2013 ATP World Tour Finals
Federer did not have the best of World Tours in 2013 as he was then going through a lot of injury struggles. Del Potro on the other hand, was having a pretty good year as he returned to the Top 5 of the ATP rankings. Both players made it to the World Tour Finals in London.Both Federer and Del Potro were drawn in Group B which meant that it would be the third consecutive tournament where the two would be locking horns, having previously met at the Swiss Indoors and the Paris Masters with Del Potro winning the title at the former, and Federer winning their quarter-final at the latter.Both players lost to Novak Djokovic and beat Richard Gasquet, which meant that their final round-robin match would be a virtual quarter-final with the winner progressing to the semi-finals. Del Potro made a brilliant start to the match by taking a 4-1 lead in the first set. Federer tried to fight back but could not stay in the set for long as Del Potro won 6-4.The second set was pretty intense and it went to a tie-break which Federer won to level the match. In the third set, Del Potro began superbly by taking a 3-0 lead and looked on course to reach the semi-finals.However, Federer held his nerve and took the set to 5-5. In the eleventh game of the set, Federer made a decisive break to serve for the match. He hit an ace to take the set and the match, thus qualifying for the semi-finals where he was eventually beaten by Rafael Nadal.
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