After finishing as the year-end no. 1 player for the first time in 2008, Rafael Nadal was off to a great start in the following season as well. The Spaniard won his first and only Australian Open crown and backed it by lifting trophies in Indian Wells, Monte Carlo, Barcelona and Rome.
Rafa suffered his first Roland Garros loss to Robin Soderling in the fourth round and skipped Wimbledon due to knee issues, hoping to bounce back in Montreal. Nadal claimed the Canada Open title in Toronto a year ago and did not have to play much to reach another quarter-final.
Still, he faced a massive obstacle in that clash and lost to Juan Martin del Potro 7-6, 6-1 in an hour and 52 minutes. It was their sixth clash and the second straight victory for the Argentine, who prevailed over Rafa in Miami five months earlier and repeated that on a similar surface to advance into the third Masters 1000 semi-final.
Juan Martin del Potro beat Rafael Nadal in straight sets in Montreal 2009.
Juan Martin served at 75% and lost 19 points in nine service games, facing one break chance in a tricky moment and saving it to mount the pressure on the other side.
Nadal stayed in touch in the opening set and led 5-2 in the tie break before dropping five consecutive points and momentum. Del Potro had a boost and stormed over Nadal in set number two to book a place in the last four. Feeling pressure in his games, Rafa faced two break chances at 3-4 in the first set and repelled those to stay competitive, closing the game with a forehand down the line winner.
Serving at 4-5, the Spaniard saved a set point following a marvelous defense and brought it home with a backhand winner for 5-5. Del Potro saved it with a backhand winner at the net, and he had to work even harder in the tie break, where Rafa moved 5-2 up with a smash winner at the net.
Juan Martin pulled a mini-break back in the tenth point when Nadal's forehand landed wide and stole the breaker with a booming serve at 6-5. Rafa got broken at 15 at the beginning of the second set and fell 3-0 down before asking for a medical timeout due to hand blisters.
Del Potro held at 15 in the sixth game to move closer to the finish line and passed it with the third break of serve at 5-1 to move into the semis.