Jack Draper’s preparations for the US Open were dealt a blow by a straight-sets defeat to Jordan Thompson in the first round of the Canadian Open in Montreal.

British number one Draper was playing his first hard-court singles match since the Miami Masters in March on the back of last week’s second-round exit to Taylor Fritz on clay at the Paris Olympics.

The 22-year-old was beaten 7-5 6-2 in little over an hour and a half as Australian Thompson deservedly set up a last-32 showdown against second seed Alexander Zverev.

With the final grand slam tournament of the year scheduled to begin at Flushing Meadows on August 26, Draper paid a heavy price for a string of unforced errors on Wednesday.

World number 30 Thompson seized the initiative with a break in game seven and eventually capitalised on his third set point after the Briton briefly brought the match back on serve.

Draper, who is partnering Australian Open champion Jannik Sinner in the doubles draw, dug in to save two break points in his opening service game of the second set and produced some eye-catching winners during the contest.

But costly double faults in games three and seven helped gift his 30-year-old opponent a route into round two.

Harriet Dart was unable to capitalise on her opportunity as a lucky loser in the women’s draw in Toronto as she slipped to an agonising tie-break defeat to Diana Shnaider.

British number three Dart looked destined for a swift exit after losing four successive games during a largely one-sided opening set against the Russian 14th seed.

The 28-year-old, who on Monday retired injured from her qualifier against American Louisa Chirico, impressively battled back to force a decider but, despite serving for the match, was beaten 6-3 3-6 7-6 (2).