The sixth seed claimed a 7-5, 6-7, 6-4 victory at the Aviva Centre in the Canadian city to record her first win over a world number one.

Wozniacki was 5-1 down in the first set and 4-2 down in the third, but recovered on both occasions to seal her place in the next round.

Plíšková was playing in her first event since moving to the top of the world rankings last month.

The Dane will now play American Sloane Stephens for a place in the final.

She defeated Czech Lucie Safarova 6-2, 1-6, 7-5.

The match between Spaniard Garbine Muguruza and Ukraine's Elina Svitolina was suspended due to rain.

Muguruza, the Wimbledon women's singles champion, currently leads 6-4 with the second set yet to begin.

Romania's Simona Halep faces Caroline Garcia of France in the fourth quarter-final tomorrow.

In the men's event, Switzerland's Roger Federer extended his winning streak to 15 matches this season as he comfortably beat Spain's Roberto Bautista Agut at the Uniprix Stadium in Montreal.

The 36-year-old won 6-4, 6-4 as he has his sights set on a third Rogers Cup title of his career and sixth tournament win of the campaign.

He will now play unseeded Dutchman Robin Haase after he came from behind to beat Argentina's Diego Schwartzman 4-6, 6-3, 6-3.

Canadian youngster Denis Shapovalov continued his remarkable run at the tournament.

After beating Spain's Rafael Nadal yesterday, the 18-year-old wild card entry overcame Frenchman Adrian Mannarino 2-6, 6-3, 6-4.

Germany's Alexander Zverev completes the final four as he defeated South Africa's Kevin Anderson in straight sets 7-5, 6-4.