By Jonathan Agnew BBC cricket correspondent at Lord's

Michael Clarke and Damien Martyn turned things in Australia's favour with a vital partnership on the second day against England.

Clarke has given us an early glimpse of his brilliance

Why can't Kevin Pietersen catch? Depending on how severe you want to be, you could now claim that he has now dropped three in the game.

Even being generous, there is no escaping the fact that the chance he missed at cover when Michael Clarke had scored just 21 was a relative sitter.

It can be difficult to see the ball sometimes with so many spectators in brightly coloured clothes in the background, but there will be concerns about his concentration.

For all his bravado and fighting talk, he has now discovered that if you give a batsman like Clarke a chance at this level, he will make you pay.

Last winter, I tipped Michael Clarke to be the batsman of the Ashes series, and he has now given us an early glimpse of his brilliance.

He scored a century on his Test debut last year, and is a real stylist with some of his leg-side strokes bearing more than a passing resemblance to Mark Waugh.

On the off side, he is busier than Waugh used to be, and he brings the added attraction of being happy to take a risk or two.

Pietersen was out-foxed by his county captain Warne

The superb running, diving catch by Damien Martyn to dismiss Pietersen.

Having hit Glenn McGrath for 14 in the previous over, including a towering six that bounced off the railings of the pavilion balcony, Pietersen then smashed Shane Warne into the middle tier of the Grand Stand.

Cunningly, Warne tossed the next delivery a little wider of the off stump, which made Pietersen overstretch a little as he tried to repeat the shot.

With one eye on the ball, and the other on the boundary rope, Martyn dashed to his left at deep mid-wicket and, fully outstretched, he dived to take the ball inches from the ground.

Pietersen had cut loose and had he remained at the crease for only a few more overs, he might have erased Australia's lead completely.

England's supporters must have experienced a familiar sinking feeling as the partnership between Martyn and Michael Clarke's started to blossom.

The fielding started to wilt - one effort by Hoggard when he let the ball go through his legs for four springs to mind - but after the fortunate dismissal of Clarke for 91, they regained their composure and rallied strongly at the end.

Australia have an imposing 314-run lead, but are by no means in an impregnable position with so much time left in the game.

They will be keen to extend that to at least 350 on the third morning.