Ashes 2013: Alastair Cook a brilliant captain - Andy Flower

Team director Andy Flower has defended Alastair Cook's "brilliant" captaincy following criticism from Australian legend Shane Warne.

England's dramatic 74-run win in the fourth Test sealed a third successive Ashes series victory over Australia.

Warne accused Cook of using "negative" tactics and likened England to an under-10 side after messages appeared to be sent to Cook out on the field.

But Flower said: "Cook has led the side brilliantly. He is a strong leader."

England's success inside four days at Chester-le-Street gave them an unassailable 3-0 lead in the five-match series.

Although Cook, 28, has struggled with the bat in this series, averaging 27, England head to The Oval for the final Test starting on 21 August aiming to seal a 4-0 series win for the first time on home soil.

But former leg-spinner Warne, the second highest wicket-taker in Test history with 708 victims, is not impressed with Cook's leadership, accusing the England management of passing messages to the England skipper during the final stages of the fourth Test in Durham.

As Australia cruised to 149-1 in pursuit of 299 for victory, Warne claims Cook received information via the 12th man during a drinks break.

When play resumed, Tim Bresnan returned to the attack after tea on day four and removed David Warner for 71. Stuart Broad's burst of 6-20 in 45 balls then hastened Australia's slide to 224 all out.

Flower added: "Cook's captaincy has been excellent and he made some decisions on Sunday that turned the game.

"Bringing on Bresnan, who got Warner out straight away, was a good decision."

Flower added that Cook was still "young" for a Test captain, but insisted he had been "strong in the dressing room and in the field".

He also said the team paid little attention to the critics.

"I'm not sure what is said off the field because we judge ourselves by our own standards in the dressing room," said Flower.

Flower admitted England have not been at their best during the series, but said his side had "held ourselves well under pressure".

He also warned of tougher tasks ahead as the teams prepare for the return Ashes series in Australia starting in November.

"We have another match and then it will be a bigger challenge in Australia; it is always a very tough series there," he said.

"We know it will be tough cricket and we are prepared."

England have never won a five-Test Ashes series four times in a row, and victory in Australia would also cap a fine year that began with a first Test series win in India for 27 years.

"This side has had some excellent results recently, but we don't sit and talk about the side being a great side. That is for other people to judge. Rankings and ratings are for other people."