Despite his valiant efforts, Haas, 34, the oldest player in the tournament, lost the third set after tying with the 25-year-old Serbian powerhouse in the first two sets.

Despite the loss, Haas, whose career high ranking was No. 2 more than a decade ago in May 2002, played no impressively against current No. 2 Djokovic with his smart, risk-taking style that delighted and thrilled the audience.

Times and again Haas sent Djokovic scrambling all over his half of the court chasing the ball, with his wicked backhand shots and uncanny ability to detect and seize every opportunity to send drop shots right off the net. He missed a few times, but succeeded more times.

But in the end, it was not enough to overcome Djokovic's dominance from the baseline. Even if he was not in his best form fresh off the Olympics matches and with lingering jetlag, Djokovic again reminded the audience why he is among the world's best tennis players as he hit the tennis ball to incredible angles on his opponent's side.

Djokovic, who appeared tense on the court, was gracious about his worthy opponent after the match.

"Tommy is a great player," he told reporters.

"After years of injuries and surgeries, he comes back very strong, very fit, plays really well on faster surfaces."

"He made a couple really good wins here and he was on the roll (sic), so it was a really tough match," said Djokovic.

Djokovic will face fellow Serbian Janko Tipsarevic in the semifinals on Saturday. Before the Djokovic-Haas match, Tipsarevic defeated Spain's Marcel Granollers on the same court.

In the other quarterfinals, Toronto's own Milos Raonic lost to American John Isner. While Isner's fellow American and the 2011 Rogers Cup runner up, Mardy Fish, went down to defeat against a surging Richard Gasquet, who upset world's No. 7 Tomas Berdych in two straight sets in today's first match in the main stadium.

Every player in the four quarterfinal matches played twice today, as the tournament schedule was condensed after rain shut down the tournament all day on Thursday.

Earlier today Isner defeated German Philip Kohlschreiber, Haas won over Czech player Radek Stepanek, and Fish overcome Juan Monaco of Argentina.