Toronto: A 45-minute rain interruption did little to stop the progress of Rafael Nadal at the Toronto Masters as he defeated Stan Wawrinka 7-5, 7-6 (7/4) to reach the quarter-finals.

The halt in proceedings came 63 minutes into the opening set after Wawrinka saved a Nadal set point for five-all, with the Spaniard then holding serve for 6-5.

When the weather passed, the pair returned, with Nadal wrapping up the set on his second chance.

The second set was a battle as the Swiss, a three-time Grand Slam champion, fought back from an early breakdown, took a 2-1 lead, with the pair again trading breaks in the fifth and tenth games.

Nadal came from a mini-breakdown in the tiebreaker and secured victory on his second match point. "It was a good match, a very positive victory for me over a tough opponent," Nadal said. "I'm happy to see Stan playing well again. We had a good quality of tennis. I'm very pleased, I needed a match like this. It does much for the confidence," he added.  

Nadal's win was his 17th from 20 played against Wawrinka.

Second seed Alexander Zverev, the holder, lined up a re-run of last week's Washington semi-final as he again takes on Stefanos Tsitsipas.

The Greek, who turns 20 on Sunday, knocked out his second seed in as many matches, stunning Wimbledon champion Novak Djokovic 6-3, 6-7 (5/7), 6-3 to reach the quarter-finals.

Zverev rolled over Russian Daniil Medvedev 6-3, 6-2 in 52 minutes while never facing a break point.

Tsitsipas called his knockout of Djokovic, "the best match of my career. I knew I was playing pretty good today." 

The number 27 will play the first Masters 1000 quarter-final of his career. "He played very well and deserved to win without a doubt," Djokovic said. "I just played not that great. "I didn't return well. It wasn't that great of a match," he added. Bulgarian fifth seed Grigor Dimitrov laboured for almost two and a half hours to subdue Frances Tiafoe of the United States 7-6 (7/1), 3-6, 7-6 (7/4).

He next faces Wimbledon runner-up and fourth seed Kevin Anderson who defeated Ilya Ivashka of Belarus 7-5, 6-3 to also make the last eight.

Sixth seed Marin Cilic continued his quiet progress, beating Argentine 11th seed Diego Schwartzman 6-3, 6-2.

Canadian teen Denis Shapovalov went down to Robin Haase, losing 7-5, 6-2, ending local interest. The Dutch winner will take on Karen Khachanov, who beat eighth seed John Isner 7-6 (7/5), 7-6 (7/1).