I backed Warner's judgment 100% - Clarke

Michael Clarke has said he backed David Warner's decision to review his dismissal from a thick outside-edge despite telling Warner he thought the ball had made contact with the bat.

Australia's use of the DRS has been poor throughout the series and that continued on the second day at Old Trafford, where Warner brought boos from the crowd when he walked to the crease and further jeers after his ill-judged referral.

The edge off Graeme Swann was deflected off Matt Prior and snapped up at slip, not dissimilar to Stuart Broad's controversial edge and non-walk at Trent Bridge. Clarke was at the non-striker's end when Jonathan Trott completed the catch to dismiss Warner, who had struck his pad with his bat at the same time as the bat hit the ball, apparently confusing his judgement.

"My reaction was, yes, I thought Davey hit it," Clarke said. "But in fairness to Davey, if you have a look at the replay, he actually hit his pad at the same time so he obviously didn't feel the ball hit the bat. We had a little discussion in the middle.

"Let's just say we disagreed, but in saying that, I did say to Davey that I would back his judgement 100%. He was confident he didn't hit it so it was worth a look and I've said before I think that's the way DRS should be used. I think if the batter feels that he didn't hit the ball then his partner should back his judgement."

Acceding to the review could have been dangerous on Clarke's part, because it left Australia at 365 for 5 with no referrals left, and a hefty first-innings score was always going to be necessary on a good batting pitch. As it turned out, Australia didn't need the DRS again, as Clarke compiled 187 - his highest score outside Australia - and Brad Haddin and Mitchell Starc pushed the total to 527 for 7 before the declaration came.

It was also Clarke's first Test century batting at No. 4, a position that he took up in this match after Phillip Hughes was dropped. Despite the success, Clarke said he was unsure if he would remain at second drop in the future or move back to his more usual position at No. 5.

"I got a hundred at No. 4, what a miracle," Clarke joked after play. "I don't know, we'll assess in the second innings let alone the next Test match. The number doesn't bother me. I've been saying it for a while. It's nice though to finally have a hundred batting at No. 4 but I'm not sure.

"I didn't feel that great yesterday or today at the crease. I felt there was enough in the wicket - I played and missed a hell of a lot and had a fair bit of luck. Don't get me wrong, I love the result. It's better than getting zero, that's for sure but I think I'll be able to assess it more if we win the Test match."

Clarke's runs, combined with valuable half-centuries from Chris Rogers, Steven Smith, Haddin and Starc, have at least given Australia a chance of the victory they need to retain any hope of winning the Ashes. The bowlers began well, collecting two England wickets after Clarke declared in the final session, but he said it was important they maintained their patience over the next three days.

"It's not the type of wicket you can force too hard," he said. "You have to build up pressure. The bowlers will have to be exceptionally consistent like they were this afternoon. It is going to take a lot of time to bowl England out. Our bowlers have the discipline. I was pleased with the way Nathan Lyon started today. There was a bit of spin but more importantly there was some bounce there for him as well. He will play a big part in both innings.

"The team should be extremely proud of the position we are in. We copped a bit of criticism after not making enough runs in the first two Test matches and rightly so. The way everybody did their job in the first innings is a credit to all the boys. We have worked exceptionally hard in the lead up to this Test match and it was nice to get the result. There is still a lot of work to do."