Opener Kane Williamson says New Zealand must produce their best performance of the World Twenty20 tournament in Bangladesh if they are to beat Sri Lanka and advance to the semi-finals.

The teams play in a virtual quarter-final in Chittagong on Monday, with both having won two from three games.

A loss to the world No.2-ranked Sri Lanka side will eliminate the Black Caps while victory would see them advance to the last four alongside South Africa.

Williamson says New Zealand have the potential to play better than they have offered in wins over England and the Netherlands and in their narrow loss to South Africa.

“We’re yet to put together the complete performance that we know we’re capable of,” he said.

“The nature of T20 is there’s a lot of things you can’t control and if one or two players step up, then we can beat anyone and we certainly have the players to do that.”

Williamson’s promotion to open has been successful at the tournament, producing scores of 24 not out, 51 and 29 at a decent clip.

His contribution will be important again against a Sri Lankan team who rely heavily on their spin bowlers.

Black Caps captain Brendon McCullum, whose 85 runs at the tournament have come off 55 balls, will be anxious to bowl first at Zahur Ahmed Chowdhury Stadium, where dew has been a factor in recent games.

Sri Lanka’s only loss came when they failed to defend 189 against England, with the slippery late conditions helping the batsmen.

Williamson says spinners clearly struggle with their grip in the dew and the seamers are also exposed, making the toss crucial.

“The ball seems to skid on more and get quite wet,” he said.

“England showed the perfect way to chase down a big total against a very good bowling attack, so it would be great to be able to copy that.”

Sri Lanka pace bowler Lasith Malinga will captain his country for the first time in the absence of Dinesh Chandimal, suspended for their slow over rate against England.

Malinga says his team are prepared if they encounter the same conditions.

Batsman Mahela Jayawardene looks set to play despite dislocating a finger against England.

New Zealand are expected to keep the same side who beat the Netherlands by six wickets on Saturday, with Trent Boult retained ahead of fellow-seam bowler Tim Southee and allrounder Jimmy Neesham preferred over Colin Munro.

Spin bowling options Ronnie Hira and Anton Devcich haven’t played at the tournament.