Ashes | Ton-up Alastair Cook leads England's reply on Day 2

Alastair Cook broke out of his recent form slump in dramatic fashion on Wednesday when he posted his first century at the Melbourne Cricket Ground, reaching the milestone in the final over before stumps as England enjoyed its best day of the Ashes series against Australia. (LIVE SCORECARD)

After surrendering the old urn by losing the first three tests of the five-match series, England finally turned the tables on the Australians, demolishing their batting lineup then making a strong reply with the bat on the second day of the fourth test.

Cook, who had struggled badly in the first three tests, prompting speculation about his future in the team, was at his imperious best. He registered the 32nd test hundred of his distinguished career to help England reach 192-2 at the close of play in reply to Australia's 327, still 135 in arrears but with momentum on its side.

"We know that we'll need three more fantastic days to win this test," England fast bowler Stuart Broad told a news conference. "It's not going to be easy to go and take 20 wickets here but we've put ourselves in a position where we could.

"We've still got a huge amount to play for."

The Australians looked set for a much bigger total before crumbling in a heap and losing their last seven wickets for just 67 runs as England's embattled fast bowlers bent their backs and dug deep on a pitch that offered little real assistance to the seamers.

While England's old guard reveled in the conditions, it was a day to forget for the Australian captain Steve Smith, who has been the standout player of the series after scoring a hundred in the first test in Brisbane and a double century in the third match in Perth.

Smith squandered his chance of another century when he chopped a wide delivery from England debutant Tom Curran onto his stumps when he was on 76, then dropped a sharp catch off Cook at slip when he was on 66. Smith then gave up 11 runs in the last over of the day to allow England's all-time leading scorer to get his hundred before stumps were drawn.

"You always want to take your catches. We know how important they are," Australian spinner Nathan Lyon said.

"It was unlucky it popped out at the last minute but hat's off to Alastair Cook, he batted extremely well and we all know how much of a talent he is."

The 33-year-old Cook batted for more than four hours and hit 15 boundaries off 166 balls to finish the day unbeaten on 104 with his skipper Joe Root alongside him on 49 not out. The pair had shared an unbroken partnership of 112 on a baking hot day that sapped the energy of all the players.

The Australians did pick up two early wickets when Lyon took a diving one-handed catch off his own bowling to remove Mark Stoneman for 15 and Josh Hazlewood trapped Vince James lbw for 17 but struggled in the absence of injured paceman Mitchell Starc and an out-of-sorts Pat Cummins, who was restricted to just 11 overs because of a stomach bug.

England's quicks avoided the worst of the heat by ripping through the Australian middle and lower order in the cooler morning session, with Broad (4-51), James Anderson (3-61), Chris Woakes (2-72) and Curran (1-65) all taking wickets.

"We should have pushed on to 400-plus but we lost wickets early. We definitely left runs out there," Hazlewood told Australian radio.

"A few of the boys know that they need to be better."

Curran, a late call-up to the team when Craig Overton broke a rib and was ruled out, justified his inclusion by triggering the Australian collapse when he snared the prized wicket of Smith to belatedly capture his first test victim.

A jubilant Curran wildly celebrated what he thought was his first wicket on day one when he had David Warner caught on 99, but his joy was short-lived when television replays showed he had overstepped the crease and bowled a no ball.

Given a reprieve, Warner brought up his century off the very next ball to add further insult to Curran's rookie error. But the 22-year-old made amends early on Wednesday morning by removing the dangerous Smith for 76 and changing England's fortunes.

Shaun Marsh, who made a century in the second test in Adelaide, chipped in with a fine 61 but four batsmen were dismissed in single figures.

Anderson's three wickets saw him move past West Indian Courtney Walsh into outright fifth place on the all-time test list with 521 wickets.

"Everyone is delighted for Cookie to get a hundred but we've got to come back and do the same tomorrow," Anderson told BT Sport.

"We've played some really good cricket on this trip but not done it for long enough."