Australia have defended their shock move to send England in to bat after the tourists reached 6-226 on day one of the fourth Ashes Test.
Kevin Pietersen, whose attitude and shot selection have been questioned all week, returned fire with a determined knock of 67 not out from 152 balls.
A world-record crowd of 91,092 packed into the MCG to see Australia captain Michael Clarke insert the opposition for the fourth time in his 20 toss victories.
Pacemen Ryan Harris (2-32 off 20 overs) and Mitchell Johnson (2-59 off 20) were constant threats to England's batting but the tourists showed some staying power as they battle to fend off a 5-0 series sweep.
"I think Michael wanted to lose this one," Harris said.
"He didn't know what to do. When he left for the toss he was batting.
"Darren [head coach Darren Lehmann] and a couple of other blokes were out there and had a bit of a chat and there was a bit of moisture in it.
"The conditions to me were a bit like Brisbane with a bit of humidity around and a bit sticky.
"So I was keen to bowl and he thought the same."
Harris denied the memory of 2010, when Australia were invited to bat first and made 98 all out, was a factor in Clarke's decision.
England vice-captain Ian Bell said he had expected Australia to bat first.
"We were going to bat," he said.
"Last time [at the MCG], bowling first, it worked for us.
"So I wasn't a little bit surprised to hear that there was talk about whether you'd bat or bowl.
"It proved to be a very good wicket all the way through the day, certainly when the sun came out."
Australia's bowling attack was unbalanced by the groin injury to star all-rounder Shane Watson, who limped off midway through his seventh over and returned later in the day to take a catch at first slip.
"The fact he got back out on the park is pretty good," Harris said.
"Whether or not he bowls again I'm not sure."
England captain Alastair Cook (27) shared an opening stand of 48 with Michael Carberry.
Dropped at third slip on two, Carberry was bowled by Watson on 38.
It was time for the main event after Joe Root was out for 24 at 3-106 when caught behind off the bowling of Ryan Harris.
Labelled a mug by Geoff Boycott, Pietersen put his head down in a 67-run stand with Bell (27).
Pietersen was caught at fine leg on six before sub fielder Nathan Coulter-Nile stumbled over the boundary and the batsman had a second life on 41 when George Bailey dropped a tough chance at mid-wicket.
Johnson removed Ben Stokes (14) and Jonny Bairstow (10) in a fiery spell with the second new ball.
Pietersen, on 63, became England's fourth-leading run-scorer, fittingly overtaking Boycott (8114).
Bell said England were hoping to push beyond 300.
"The positive is we have Kev there tomorrow morning and if he has a good couple of hours, things can change very quickly," Bell said. AAP