Australia's narrow win over Afghanistan on Friday sent New Zealand through to the T20 World Cup semi-finals and set England a straightforward target to join them.

England need only a victory against Sri Lanka in Saturday's final Group 1 match to be sure of a place in the last four.

Hosts and defending champions Australia had been facing an uphill battle to improve their run rate ever since an 89-run thrashing at the hands of the Black Caps in their opener.

With their meeting with England rained off, the margin of victory in other matches was going to prove pivotal.

Although Australia survived a scare in beating Afghanistan by four runs, that tight affair left their net run rate at -0.173, below England's mark of +0.547, which will improve further with victory over Sri Lanka.

The home nation therefore need Sri Lanka to defeat England and keep them in the top two on seven points.

Stand-in Australia captain Matthew Wade said: "We'll stay the extra night here and watch that game. We'll be hoping for a little bit of an upset there, obviously.

"That's tournament play – we put ourselves in this situation straight from the get-go this time. Although we've been trying to chase a little bit of run rate, it just hasn't really gone our way.

"We've been a little bit slow getting out of the blocks in this tournament. Hopefully it doesn't cost us."

Glenn Maxwell struck a similar tone, saying: "We'll certainly be following it. We've obviously put ourselves in this situation, but hopefully Sri Lanka can do the job for us."

Although Maxwell scored an unbeaten 54 off 32 against Afghanistan, he added: "It was quite hard to press the issue.

"We probably got to about the 12-over mark, where we just had to put a total on the board to make sure we gave ourselves a chance of winning the game.

"Even though we were trying to go hard at the back end, they bowled extremely well."

If Sri Lanka can do Australia a huge favour, Wade is "very hopeful" skipper Aaron Finch and all-rounder Tim David will return for the semi-finals.

David was "really, really close" but failed a late fitness test on Friday, Wade added.