Juan Martin Del Potro, right, shakes hands with Roger Federer after qualifying for the semifinals of the ATP World Tour Finals with victory over the 17-time grand slam champion.
Del Potro's day —
Juan Martin Del Potro, right, shakes hands with Roger Federer after qualifying for the semifinals of the ATP World Tour Finals with victory over the 17-time grand slam champion.
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Two-time defending champion Federer was disappointed to lose, despite having already secured a place in the last four of a tournament that he has won a record six times.
Federer's frustration —
Two-time defending champion Federer was disappointed to lose, despite having already secured a place in the last four of a tournament that he has won a record six times.
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Del Potro last played in the season-ending tournament in 2009, when he lost in the final. Since then the Argentine has battled his way back into the top 10 following a serious wrist injury.
Argentine advances —
Del Potro last played in the season-ending tournament in 2009, when he lost in the final. Since then the Argentine has battled his way back into the top 10 following a serious wrist injury.
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Del Potro's win ended the hopes of Spain's world No. 5 David Ferrer, who reached the semifinals last year and was runner-up in 2007 when the elite eight-man event was held in Shanghai.
Forlorn Ferrer —
Del Potro's win ended the hopes of Spain's world No. 5 David Ferrer, who reached the semifinals last year and was runner-up in 2007 when the elite eight-man event was held in Shanghai.
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