Two houses and a shed have been destroyed as lightning strikes sparked more than 100 new blazes in a state already ravaged by fires.
The properties were caught in a fire that started at Nangiloc, in the far northwest of Victoria.
It was one of 114 fires to break out, mostly from dry lightning, in the heat and storm that battered the state on Sunday and early Monday.
The 4WD ute of a NSW fire crew responding to a fire at Little Desert National Park caught alight and was destroyed, Emergency Management commissioner Rick Nugent said.
"Thankfully, the firefighters, three of them, managed to escape the vehicle before it was fully engulfed."
A blaze in the Little Desert National Park, about 375km west of Melbourne, was declared contained but broke away on Sunday afternoon.
The Little Desert fire covers 84,000 hectares, while dual fires burning in the Grampians total 46,000 hectares.
Crews battling the Little Desert fire faced a hard slog on Monday, when the fire broke containment lines and moved rapidly into agricultural land.
Firefighters are preparing for an even tougher day on Wednesday as southerly winds make conditions worse.
The Grampians fire was a "long way from over", Forest Fire Management Victoria chief fire officer Chris Hardman said
He said winds from the north were putting stress and pressure on communities in the Victoria Valley, Victoria Point, west of Cavendish and Rocklands Reservoir.
Fire crews were working hard to contain the fires with with the help of bulldozers, heavy equipment and aviation assets.
"We have had more than 600 firefighters working on that fire over the last couple of days," Mr Hardman said.
"They will be there for some time to come ... it's a long way from over."
An emergency warning remains in place for the Grampians fire not yet under control.
Additional watch and act orders have been issued for four fires in the Great Otways National Park in Victoria's southwest, at Apollo Bay, Cape Horn, Hordern Vale and Cape Otway.
Severe thunderstorms swept across Geelong and Melbourne on Sunday night, bringing heavy rain, lightning, hail and damaging winds.
Power was cut to at least 45,000 homes but fewer than 3500 were still off the grid by 4pm Monday.
Geelong and Lara to its north were hit particularly hard with flash flooding, downed trees causing property damage and reported hail stones of 2cm to 4cm, according to the Bureau of Meteorology.
Some 63mm of rain was recorded at Lara, 52mm at Avalon Airport, 48mm at Clunes and 47mm at Geelong.
A lightning strike is believed to have caused a fire at Taylors Lakes in Melbourne's northwest about 1am.
The lightning and thunder across Melbourne lasted from 8pm to 3am.
The storms gave way to blazing sunshine on Monday, with a top of 37C for Melbourne, 35C for Bendigo, 34C for Geelong and 34C for Ballarat, with more afternoon storms predicted.
A cool change is due to move through South Australia on Tuesday afternoon before crossing into Victoria and Tasmania.
It will then be Western Australia's turn for heatwave conditions later in the week.
Seven out of nine Victorian regions had high fire danger ratings on Monday.
