Formula One’s season opener in Australia promises to be a pressure-packed affair after qualifying was shunted to race day following heavy rain on Saturday.

All teams face the added pressure of loading two days’ work into one after persistent rain and fading light forced organisers to delay the final two qualifying sessions until race day.

The sessions are now scheduled for Sunday morning ahead of the twilight race at Melbourne’s Albert Park.

Red Bull team principal Christian Horner admits his team and drivers will be under heavier pressure than normal.

“It’s definitely a bit more pressure because you’ve got to fit what you’d normally do over two days into a single day,” Horner said.

“But it doesn’t change our focus and approach and hopefully the weather will be a bit nicer.”

Improved weather is expected for Sunday, though conditions are expected to be unsettled with possible rain.

But it is not expected to be anything like the heavy downpour which ruined qualifying on Saturday, turning several F1 cars into Meccano sets in slippery and difficult conditions.

Mercedes’ Nico Rosberg was the pacesetter, followed by the Ferrari of Fernando Alonso and Romain Grosjean’s Lotus.

Australian Mark Webber was fifth fastest in his Red Bull, and fellow Aussie Daniel Ricciardo was 14th – both safely into the second qualifying session.

Horner echoed the thoughts of most on the F1 grid, believing the postponement was the correct decision for driver safety.

“It’s dark now. If we were running now it’s not safe for the drivers in these conditions,” Horner said on Saturday night.

“Plenty of time tomorrow to come back and qualify at 11 o’clock ahead to the race at five (pm) so it’s 100 per cent the right decision.”