London, UK, 21 June 2017 | AAP

Thanasi Kokkinakis has claimed the biggest win of his career, beating world No.6 Milos Raonic 7-6(5) 7-6(8) in the opening round at Queen’s Club.

The South Australian, in just his fifth match in almost a year following shoulder surgery and groin, abdominal and pec injuries, saved eight break points in the opening set before pinching a vital point on the Canadian’s serve in the tiebreak.

The second set followed a similar path before Kokkinakis claimed victory after another tight tiebreaker against last year’s beaten finalist at both Queen’s and Wimbledon.

> READ MORE: Kokkinakis putting injury woes behind him

The 21-year-old trailed 3-6 in the tiebreak before hanging tough; on his second match point he survived a slip before belting an off-backhand winner to seal victory, celebrating vociferously.

“It’s everything. This match was huge for me… to be out of the game so long… first top 10 win and to do it on a court like this,” a visibly emotional Kokkinakis told the BBC.

“I’m trying to look forward; it has been brutal. I am trying to get myself going week by week … it was almost 22 months out of the game or something crazy like that.

“I can’t wait to play my next round. It was a bit ugly in that first set but I am happy with the win.

“I had the chance and I got a bit lucky with him up 6-3 (in the tiebreak); it’s usually game over. I got a bit lucky and trust me I was tight on the last point but I was like ‘F’ it, I’m going for it’.”

Kokkinakis next faces either Daniil Medvedev or Nicolas Mahut.