Montreal, QC, Canada, 11 August 2017 | AAP

Injury-plagued Nick Kyrgios has suffered his first loss to fellow young gun Alexander Zverev, going down in straight sets in the Rogers Cup third round in Montreal.

The Australian was beaten 6-4 6-3 in 73 minutes by the world No.8 on Thursday.

The 22-year-old Kyrgios was broken in third game of the first set before being unable to take six chances to break back.

He was less competitive in the second set, dropping serve twice including the last game to love to hand the German fourth seed a place in the quarterfinals.

Kyrgios, ranked No.24 in the world, appeared to be battling soreness throughout the match and received treatment to the hip which forced his retirement from Wimbledon.

He faded in the second set, winning only 33 per cent of points on his second serve and being unable to take two break points in the penultimate game.

He could only save one of four break points for the match.

Kyrgios had won his two previous meetings with 20-year-old Zverev, both earlier this season at back-to-back events in Indian Wells and Miami.

Zverev will meet South African Kevin Anderson in the final eight after Anderson’s 6-4 6-1 win over American Sam Querrey.