A peaking England find themselves in a tussle with Australia for a place in the semi-finals of the T20 World Cup but skipper Jos Buttler will have the advantage of having a clear mind as the English would need nothing but a win against Sri Lanka in their final group match in Sydney on Saturday to go through.

New Zealand became the first team to reach the semi-finals following a win over Ireland in Adelaide on Friday but the defending champions Australia will need the Lankans to beat England in today's game.

2010 champions, England are on five points, and have a far superior net run-rate meaning they would need just a win to deny arch-rivals Australia a place in the top four.

"I guess we're pretty confident with whatever we need to do, we've got the skills and firepower to do it," England opener Alex Hales told a new conference on Friday.

"It all comes naturally to us, especially with the layout of our squad, playing an extra batter, the middle order is so strong.

"It's a very confident batting unit so we'll be able to adapt to whatever tomorrow needs."

Shocked by Ireland in a rain-hit Super 12 contest, England looked to be in their element during the 20-run victory against New Zealand with Buttler leading by example with the bat.

England have their destiny in their hands and Hales said he was confident of England making the last four.

"It's a pretty tight competition, and to get through is difficult," he said.

"It would be a good achievement if we can get through, in a pretty tough group in my opinion."

Openers have struggled in the tournament so far but both Hales and Buttler smashed half-centuries against New Zealand.

Their deep batting and surfeit of all-rounders make England favourites against Sri Lanka, who needed Afghanistan to beat Australia yesterday to have any hopes of progressing in the tournament.

Even though Sri Lanka are out of the equation for the semi-finals, Sri Lanka batter Bhanuka Rajapaksa said the Asia Cup champions, guided by former England coach Chris Silverwood, were simply looking to end their campaign on a winning note.

"Unfortunately not all the results have come our way, but tomorrow's game is quite important to end on a high note," the 31-year-old said.

"We just want to play good cricket and justify our presence in Australia. That's about it."

Hales, recalled to the England set-up after a three-and-a-half-year exile following two failed recreational drug tests, is wary of a "tricky" Sri Lanka "with some handy operators".

"So we are going to have to play our best cricket to win, but as I said, we are pretty confident, the mood is good in the camp and we feel like we can deal with anything they throw at us," he said.