Wimbledon champion Andy Murray lost for the first time since May to an in form Ernest Gulbis in the third round of the Montreal Open.
The 38th seed Latvian Gulbis stunned Scotsman Murray 6-4, 6-3 in one hour 28 minutes to reach the quarter-final of the Rogers Cup.
Murray will have the doubles, where he has teamed up with fellow Scot Colin Fleming, to contend with, before moving on to next week’s Cincinnati Masters ahead of the defence of his US Open title in New York later this month.
“The goal is to try and peak at the US Open,” Murray said after the loss.
“But to do that you need to make sure you prepare yourself well.
“There’s obviously some things for me to work on, but I think that will come with playing matches.”
Murray, who has won the championship twice, missed the first chance of the match with two break points in game eight, and couldn’t contain Gulbis thereafter.
Fourth seed Rafaeal Nadal earlier beat Wimbledon semi-finalist Jerzy Janowicz 7-6 (8-6), 6-4, while top seed Novak Djokovic needed three sets to overcome Denis Istomin 2-6, 6-4, 6-4.