Upsets bookended the Rogers Cup on Monday with Ukrainian teen Dayana Yastremska beating British 13th seed Johanna Konta 6-3 6-2 early on in Toronto before Maria Sharapova fell 4-6 6-3 6-4 to Anett Kontaveit under the lights in the evening session, reports Reuters.
Estonian Kontaveit battled back from a set and a break down in the first-round match to defeat the five-time Grand Slam champion, who entered the tournament as a wild card after injuries kept her out of action for much of the season.
The Russian sent a forehand service return long on match point to end the engrossing two hour and 41 minute battle.
Kontaveit will next face either seven-time Grand Slam champion Venus Williams or Spain's Carla Suarez Navarro, who play their first-round match on Tuesday.
Earlier in the day, Yastremska, ranked 33rd in the world, squandered four match points but took her fifth opportunity, dispatching Konta with the clock barely ticking past noon on the Toronto hardcourt.
Meanwhile, Canadians Denis Shapovalov and Milos Raonic fed off a supportive home crowd to advance in straight sets to the second-round of the Rogers Cup in Montreal on Monday.
Shapovalov defeated France's Pierre-Hugues Herbert 6-3 7-5 to snap a five-match losing streak while Raonic crushed 16 aces en route to a 6-4 6-4 win over another Frenchman, Lucas Pouille, earlier in the day.
Their victories helped keep the nation's hopes of a homegrown men's singles champion alive. The last Canadian man to triumph at the event was Robert Bedard in 1958.
Another promising young Canadian, 18-year-old Felix Auger Aliassime, will be in action on Tuesday when the Montreal native faces compatriot Vasek Pospisil in the first round.