Allrounder Asela Gunaratne has blasted Sri Lanka to a stunning two-wicket T20 win over Australia in Geelong.

He hit the match-winning boundary off the last ball on Sunday night to cap his outstanding 84no from 46 balls, as Sri Lanka snatched the win from the home team’s grasp.

Sri Lanka have an unbeatable 2-0 lead in the series ahead of Wednesday’s last game at Adelaide Oval.

Australia are yet to beat Sri Lanka in a home T20 after five games.

Gunaratne’s innings featured six fours and five sixes, including four sixes and three fours in the tumultuous last two overs.

Chasing 173, Sri Lanka slumped to 5-40 and with two overs left, they were still off the pace at 7-138.

But Gunaratne blasted three sixes and a four off Moises Henriques, meaning they needed 14 off the last over.

After Nuwan Kalesekara was dismissed off the first ball, Gunaratne belted a four and a six off Andrew Tye.

As was the case in game one, it came down to the last ball of the match, with Sri Lanka needing two to win.

Gunaratne smashed another boundary, sparking wild scenes of jubilation among the Sri Lankans as they reached 8-176.

He also top-scored with 52 in Friday night’s win.

Earlier, Australia’s under-strength attack had torn through the Sri Lankan top order as paceman Jhye Richardson impressed on debut and Andrew Tye was on a hat-trick.

Moises Henriques scored his first T20 international half-century. Photo: Getty

But the first full international cricket match in Geelong attracted an underwhelming crowd of 13,537, with unseasonably poor weather undoubtedly hurting the attendance.

Richardson is one of the series’ Australian T20 debutants along with 36-year-old Michael Klinger, who followed up his 38 in game one with 43 on Sunday.

Henriques paced the Australian innings with an unbeaten 56, his first T20 international half century, while Kulasekara ended the innings with three wickets in four balls.

Gunaratne also took the key wicket of Ben Dunk, who had blasted 32 runs from 14 balls.

Australia made a surprise omission by leaving out legspinner Adam Zampa, who impressed on Friday night.

-AAP