Top seed Novak Djokovic remained the last elite player in the field at the Toronto Masters as the defending champion advanced to the quarter-finals on Friday.

Djokovic’s 6-4 6-4 defeat of Sam Querrey in 65 minutes was interrupted for two and a half hours by a rainstorm at the weather-plagued event.

The result set up a clash against in-form German Tommy Haas, who defeated Czech Radek Stepanek 2-6 6-4 6-1.

The 34-year-old Haas has played three finals since June when he won Halle over Roger Federer.

He has also beaten Djokovic in their last two meetings, but they were both six years ago when the Serb was just starting his career.

Djokovic and Querrey struggled amid the interruption to finish, with the American limited to just three aces.

A brief dry period earlier in the day put three seeds into the last eight.

Richard Gasquet added to the woes of Czech Tomas Berdych, who exited the London Olympics in the opening round last week, with the Frenchman knocking out the fourth seed 6-4 6-2.

Berdych is a three-time quarter-finalist, while Gasquet finished runner-up to Roger Federer in 2006.

Serb Janko Tipsarevic beat Croatian Marin Cilic while American Mardy Fish scored a hard-fought 2-6 6-1 6-4 victory over Argentine seventh seed Juan Monaco.

Fish missed two and a half months this season due to an accelerated heartbeat problem but played last week’s semis in Washington. Monaco had won their three previous matches.

Unless weather co-operates over the weekend, the pre-US Open event could still be facing a possible delayed Monday conclusion.

“Monday is a possibility, but we’ll get there after probably tomorrow night and have that discussion,” said tournament director Karl Hale, who has already lost seeds including Olympic gold medallist Andy Murray (knee injury) plus bronze medallist Juan Martin del Potro and doubles silver medallist Jo-Wilfried Tsonga to opening defeats.

“As of right now, we’re still on schedule to finish our 7pm final (local time) on Sunday.”

The afternoon final was moved back into the evening so as not to conflict with Olympic closing ceremonies in London.