CENTURY-MAKER Alastair Cook paid tribute to Glenn McGrath after the veteran seamer took two late wickets to put Australia within touching distance of regaining the Ashes.

Cook defied the Australian attack for almost seven hours on day four to record his first Ashes ton, but McGrath struck less than three overs before the close.

Armed with the second new ball, he had the 21-year-old caught behind by Adam Gilchrist for 116 before bowling nightwatchman Matthew Hoggard two balls later.

Kevin Pietersen and Andrew Flintoff survived until the close but Australia now need just five wickets on the final day to take the urn back and clinch the series with two Tests to spare.

"The last few overs showed why Glenn McGrath has taken over 500 Test wickets," said Cook.

"I was desperate to hang on to the end but it was a decent ball and turned out to be a fantastic over when he got Hoggy.

"It's really disappointing that I couldn't get through to the end but I would have settled for a hundred at the start of the day.

"It wasn't easy all day but it's an amazing feeling to score my first Ashes hundred and hopefully that's the first of many.

"We fought all day and if Freddie and KP can get through the first session then who knows what might happen."

But if Pietersen and Flintoff are to keep the series alive they will have to match the application of Cook and Ian Bell.

Resuming on 19 for one the young pair resisted everything the hosts could throw at them.

They refused to be bullied and, in contrast to the capitulation in Adelaide, they took every opportunity to keep the scoreboard ticking over.

Bell was at his fluent best and had no problems picking off Shane Warne.

The leg-spinner has targeted Bell for special attention with his sledging but the Warwickshire batsman left Warne speechless as he hoisted him over long-on on his way to his third half-century of the series.

The second wicket partnership had reached 170 when Bell made his first mistake.

On 87 he tried to lift Warne over the top of Justin Langer at short mid-off but only succeeded in finding the hands of the fielder.

The run-rate then ground to a halt as Warne and the metronome Stuart Clark gave Cook and Durham's Paul Collingwood precious few scoring opportunities.

It took Cook and Collingwood 75 balls to add 15 before Clark ended the struggle when he persuaded Collingwood to prod outside off stump and Gilchrist held on.

Pietersen, who continues to have the upper hand on the Australian bowlers, picked up the scoring rate and lifted the pressure on Cook's shoulders.

Cook kept his cool into the final session and went to his fourth Test century with a scrambled single to square leg off Warne.

The vital fourth wicket partnership had added 76 when disaster struck with 16 balls left.

Cook, who had left the ball outside his off-stump superbly throughout the day, nibbled at McGrath and Gilchrist did the rest.

The wicket gave England's nemesis an almighty lift and he bowled Hoggard with a beauty that would have embarrassed many better batsmen.

Flintoff played and missed at his first two balls but he hung on, with Pietersen unbeaten on 37.

The England skipper has found no batting in five innings to date but will have to find some form if England are to keep the Ashes alive