Alex de Minaur is out of the Canadian Open at the quarter-final stage, losing to USA fourth seed Ben Shelton in straight sets 6-3 6-4.
It was a tight match across one hour, 32 minutes but the American converted three of his five break points to get the win and set up a semi-final against fellow American Taylor Fritz.
Having won the Washington Open last week, De Minaur looked fatigued at times throughout the contest as he played his eighth match in 14 days.
The Aussie will now turn his attention to the Cincinnati Masters, which is the last big tournament before the US Open.
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Both players fended off break points as it remained on serve for the first five games in a tight opening set
However, Shelton only need one break point to go ahead 4-2 in the sixth game and the set remained on serve until the American served it out at 6-3.
The world no.7 continued his momentum in the second set, securing an early break to lead 2-1.
But De Minaur displayed all his fighting qualities to strike back and immediately break in the next service game.
The Aussie would have been hoping to kick on through the rest of the set, but he handed the break straight back to Shelton with a double-fault to go behind 2-3.
Games remained on serve for the rest of the match as the American fourth seed moved into a semi-final against compatriot Fritz.