Kevin Pietersen claimed a key wicket with the last ball of the day following his earlier heroics with the bat to give England real encouragement in their pursuit of victory in the second Ashes Test in Adelaide.

The batsman, who scored a career-best Test score of 227 to help England to 620 for five declared, struck with his occasional spin to unseat Michael Clarke for 80 after he had looked to be in for the long haul alongside Australia team-mate Mike Hussey (44 not out).

The fourth-wicket pair had given Australia, set 375 to make England bat again, hope of forcing a draw but the dismissal of Clarke gives the tourists added impetus heading into the final day. The hosts closed on 238 for four and were left hoping that the forecast adverse weather comes to their aid on Tuesday in a bid to keep the series level.

Australia's survival prospects were enhanced by an opening stand of 84. But Graeme Swann, bowling unchanged for 24 overs in tandem with pace, then took two early-afternoon wickets.

First, Simon Katich (43) followed an off-break and got a faint edge behind on the back foot just after lunch, then Ricky Ponting, on a king pair but beginning to look comfortable once he cut Swann for four after 13 balls on nought, slightly closed the face pushing forward and was expertly caught low down to his left by Paul Collingwood at slip.

Things were really looking up for England after Steven Finn had Shane Watson (57) edging low to slip, before play was delayed by bad light and rain with Australia on 175 for three.

When the match resumed, Clarke and Hussey looked secure and confident, however, England secured a huge psychological boost as Pietersen removed Australia's vice-captain, who inside-edged on to his thigh pad with the ball ballooning up for an easy catch by Alastair Cook.

Earlier in the day, Pietersen further demonstrated his batting prowess and Bell (68 not out) added a second half-century from as many attempts in this series before England decided they had enough runs.

Pietersen went one ball after clubbing Xavier Doherty for a leg-side four to post his highest Test score, edging an attempted repeat to slip. His 308-ball innings contained 33 fours and one six.

Matt Prior chipped some handy quick runs too - having escaped a faulty slog-sweep high into the leg-side off Doherty, Ponting and Marcus North shambolically allowing the ball to drop safely between them when either one might have made the catch.