Stuart Broad didn't let his captain down.
Steaming in from the Lumley End backed by roars of the crowd, Broad sent down another fierce delivery that Australia tail-ender Peter Siddle lofted harmlessly to mid-off, where James Anderson took a simple catch.
England had won the fourth test — and confirmed its dominance over its greatest cricketing rival in the process.
"We'll enjoy what is a very special day," Cook said, "and one that I'm going to look back on with huge fondness."
A day of 15 wickets and high tension at Chester-le-Street will forever be remembered for Broad's devastating bowling performance.
Set a victory target of 299 on day four, Australia collapsed from 168-2 to 224 all out in just shy of two hours in a final session Monday that saw nine wickets fall in total.
Broad took six of them, finishing with 6-50 and career-best overall figures of 11-121. And, of course, the man-of-the-match award.
England won by 74 runs to take a 3-0 lead in the five-match series. The final test is at The Oval starting Aug. 21, where Australia is looking simply to save face.
"We got outplayed, Stuart Broad bowled a couple of outstanding spells and as soon as we lost Chris Rogers (for 49, to make it 109-1), we found it difficult," Australia captain Michael Clarke said.
"We've got to play better than that," he added. "We need some time to let this sink in."
Retaining the urn, which they did after the drawn third test at Old Trafford last week, was one thing. But winning a third Ashes series in succession for the first time since the so-called "Botham's Ashes" of 1981 really is something to savor for a team that lost eight on the bounce between 1989 and 2003.
Despite their improvement over the past two weeks, the Australians' winless streak in tests moved to eight — a sorry record for such a proud cricket nation.
England, whose unbeaten run in tests stretches to 11, lost the final five wickets of its second innings for the addition of 96 runs to the overnight 234-5. That meant it stayed in the driving seat in a fluctuating test.
Ryan Harris took four wickets to claim a career-best 7-117 — becoming the first Australian since Shane Warne in 2001 to take so many victims in one Ashes innings — but agricultural knocks of 45 from Tim Bresnan and 30 not out from Graeme Swann proved crucial in taking the game away from the tourists.
Even so, things looked rosy for the Australians when Rogers and David Warner put on an opening stand of 109 — the team's best first-wicket partnership of the series.
Rogers edged Swann to Trott at first slip but Warner stayed in the groove, uppercutting Broad for four and smashing Swann over extra cover for the only six of the match.
Even when Usman Khawaja (21) was trapped lbw to Swann to make it 147-2, Clarke came in, hit three quick fours and ensured the momentum was still with the tourists.
Then it all went wrong.
Warner edged a beauty from Bresnan to wicketkeeper Matt Prior to go for 71, and Broad bowled Clarke (21) with a pearler off the seam.
The crowd came to life. England's fielders suddenly chirped up.
"Cooky threw me the ball and said, 'Spice it up a bit,'" Broad said. "I got a good partnership going with Tim Bresnan, we tried to hit the deck as hard as we could and we managed to do it."
Steve Smith (2) dragged a 90 mph delivery from Broad onto his own stumps as he attempted a pull and the paceman then trapped Brad Haddin lbw for 4. He wheeled away in celebration, puffing his cheeks and with his eyes bulging.
In 55 minutes, the whole middle order had been removed. So had Australia's hopes of squaring the series.
"He really charged in," Cook said of Broad. "When everything clicks and he's bowling in the high 80s with the control Broady has, it's incredibly hard to bat.
"Words can't justify how good a spell of bowling that was."
Then it was just a case of wrapping up the tail.
Harris (11) was plumb lbw to Broad, who then bowled Nathan Lyon for 8 to bring up his second five-fer of the match.
With darkness descending and spectators straining their eyes, England was allowed an extra half-hour to take the last wicket — and they needed 16 minutes of the allotted time.
In that crazy final session, Australia lost nine wickets for 104 runs, with Broad hitting one of those purple patches he is known for.
"The guys are very proud in that dressing room," Broad said. "There's a group in there who have won three (series) from three, and there is a real hunger in there that you want to achieve more."
That's something the bruised and battered Australians won't want to hear. They will have their chance for revenge in the return series Down Under starting in November.
