BIRMINGHAM, England, July 7: Damien Martyn more than repaid the faith shown in him by the selectors at the expense of the dropped Justin Langer as he hit his highest Test score of 99 not out to help steer Australia to 486 for five at tea on the third day of the First Test against England here at Edgbaston on Sunday.

Martyn, playing in his 21st Test innings, shared an unbroken stand of 150 with Adam Gilchrist, who was 81 not out with Australia an imposing 192 ahead.

Martyn had faced 162 balls including 14 fours and one five, while Gilchrist, who gave Martyn a 34 run head start, had faced 94 balls including one six and 10 fours.

The 29-year-old Martyn's previous best was 89 not out against New Zealand at Hamilton in 1999-2000.

The pair were playing in their first Ashes Test and both could well become the first Australians since Ricky Ponting at Headingley four years ago to make a century on debut against England.

But England missed opportunities to dismiss both batsmen and that proved costly for Nasser Hussain's team.

After a 59 minute break for bad light and rain that spanned the lunch interval and saw 15 overs lost Australia resumed at 381 for five.

Within the space of five balls England saw two opportunities to dismiss first Gilchrist, then Martyn, for their respective interval scores of 14 not out and 65 not out disappear within the space of five balls.

First Gilchrist failed to get on top of an angled steer against Andrew Caddick and the ball only just eluded the right hand of the diving Craig White at gully.

But there was far worse to come for England as Martyn followed an outswinging delivery from Caddick's new ball partner Darren Gough and got a thick outside edge.

The ball was heading straight into the hands of Michael Atherton at first slip but wicket-keeper Alec Stewart, diving across to his right, spilled the catch with Australia 387 for five, a lead of 93.

Had England taken both these chances they would have been into the tail with no specialist batsman at the crease.

In all they had missed four clear-cut chances in the match and that is too many against Australia.

Martyn sensibly continued with his attacking approach and for all his good fortune he did play some fine strokes.

None was better than the cover-driven four off White that brought up a century partnership with Gilchrist from 139 balls.

Gilchrist reached his fifty from 70 balls including seven fours with a single off left-arm spinner Ashley Giles, whom he drove for a straight six.

Earlier, just as he had done on Friday, when he bowled Michael Slater (77), Gough dismissed the leading not out overnight batsman early in the day's play.

Australia captain Steve Waugh, England's chief tormentor Friday, had added just four to his 101 not out when, to the 12th ball of an overcast morning, he was caught on the crease by a good length Gough delivery.

West Indian umpire Steve Bucknor nodded his head several times but no batsman ever 'walks' for an lbw even though he was plumb out.

However, the finger eventually went up, Waugh dismissed for 105 off 181 balls including 13 fours.

Australia began on 332 for four, with Martyn 34 not out. But they did not have an easy start against an accurate Gough and Caddick.

However, Martyn did strike two resounding fours from successive Gough deliveries, first cutting him and then using the away swing for an off-drive high over point.