Alastair Cook reached a maiden Test double-hundred as England consolidated their remarkable run-laden rescue act to make the first Ashes contest safe by lunchtime on the final day at the Gabba.

Cook (201no), who had on Sunday shared England's ground-record opening stand with his captain Andrew Strauss, was part of a new best at this venue for the second wicket too as he and Jonathan Trott scored 251 together. Trott (100no) added a century of his own out of an astounding 439 for one, which put England 218 runs in front with two sessions left.

This is only the second time in England's history the top three have reached three figures in the same innings - and the first since Jack Hobbs, Herbert Sutcliffe and Wally Hammond managed the feat in 1924.

It is a unique Ashes achievement for a team who had set out late on the third day needing 221 runs just to make their hosts bat again and, according to many experts, with scant chance of escaping Brisbane 0-0.

After Cook and Trott had piled on another 130 runs from just 32 overs, it was hard to imagine how the sunny morning could have gone much better for England or any worse for their opponents. Australia had been in the field for more than four sessions, and were beginning to look incapable of helping themselves.

That was certainly the impression when Michael Clarke, who had dropped barely a half-chance on Sunday when Trott was 34, put down a much easier one at slip after the same batsman glided a cut much too fine off Shane Watson on 75.

An over later, Mitchell Johnson - operating at no runs, no wickets and one dropped catch so far in this series - hurled a wide so far down the leg side it could be interpreted as symptomatic of a dispirited team.

Two sets of consecutive leg-byes when Xavier Doherty's turn defeated Cook and Brad Haddin brought up England's 400. They were not necessarily the wicketkeeper's fault but came as another blow to home morale, in front of a small crowd dominated by English cheers. Cook and Trott's smattering of boundaries in the first hour were largely from controlled edges rather than the middle of either bat.

Yet a wicket seemed unthinkable at times on a pitch which - despite ever widening cracks - was apparently better than ever for batting. Watson switched to the Vulture Street end, only to concede the cover-driven boundary - through the errant Marcus North's hands - which took Cook past his previous Test best of 173, against Bangladesh in Chittagong seven months ago.

Before the morning was out, he had become only the fourth Englishman to make a double-century down under - having batted for nine hours and hit 23 fours from 361 balls. Trott deserved much more than a footnote too when, just before lunch, he posted his second Ashes hundred from 213 balls.