Nick Kyrgios in 'the trickiest' situation

Nick Kyrgios called his US Open first round win over Thanasi Kokkinakis "the most embarrassing match of his career"

as he came through in straight sets to progress at Flushing Meadows.

Late Monday night, the doubles partners and good friends were due to face off for the first time.

Kyrgios and Kokkinakis doubled stardom at the Australian Open earlier this year by winning the tournament.

The former first met as individual contestants and was considered one of the favorites against the world number 70.

Despite making it to the Wimbledon final last month, Kyrgios entered the US Open in 23rd place.

but many expect him to take another barnstorm run.

He wasted no time in finishing Kokkinakis with a routine 6-3, 6-4, 7-6 win to kick off his campaign.

although he later explained that the mental battle was far from easy.