Michael Clarke scored 125 not out yesterday to lead an Australian fightback on the fourth day of the second Test, with England 208 runs in front yet requiring five more wickets to lead 1-0 in the Ashes series.

Having been set a world-record 522 to win after England declared at the start of the day in pursuit of their first Test victory over Australia at Lord's since 1934, the visitors were 313-5 when bad light stopped play.

It was Clarke's 11th Test hundred and he added 185 in an unbeaten sixth-wicket stand with Brad Haddin, who was on 80. Clarke batted for 257 minutes and hit 13 boundaries. Haddin lasted for just over three hours and faced 126 balls.

Australia, seeking to retain the Ashes, were on the receiving end of three questionable umpiring decisions.

World-record chase

Hoping to surpass the previous world-record run chase of 418, Australia lost their first wicket on the 19th ball of the day when ever-threatening fast bowler Andrew Flintoff had Simon Katich caught at gully for 6.

TV replays showed Flintoff had overstepped at the bowling crease and a no-ball should have been called by umpire Rudi Koertzen, standing in his 100th Test.

Phillip Hughes, dropped on 16 by Flintoff off James Anderson, made only a run more when he edged Flintoff to Strauss at first slip. Hughes reluctantly walked off after Strauss claimed the catch, but his captain Ricky Ponting told him to wait.

The umpires discussed the incident and Billy Doctrove confirmed from square leg that the catch was taken cleanly and, therefore, replays were not used. Magnified slow-motion replays failed to confirm the catch was taken cleanly.

Ponting looked annoyed. His teammate Nathan Hauritz claimed a catch against England's Ravi Bopara on Saturday and that time the batsman was reprieved when the third umpire was called and studied inconclusive replays.

SCOREBOARD

England 1st innings: 425

Australia 1st innings: 215

England 2nd innings

(Overnight 311 for six)

M. Prior run out 61A. Flintoff not out 30S. Broad not out 0Extras: (16b, 9lb, 5nb, 1w) 31TOTAL: (for six wickets declared) 311

Overs: 71.2.

Fall of wickets: 1-61, 2-74, 3-147, 4-174, 5-260, 6-311.

Bowling: Ben Hilfenhaus 19-5-59-0 (3nb), Mitchell Johnson 17-2-68-0 (1w, 1nb), Peter Siddle 15.2-4-64-2, Nathan Hauritz 16-1-80-3 (1nb), Michael Clarke 4-0-15-0.

Australia 2nd innings

P. Hughes c Strauss b Flintoff 17S. Katich c Pietersen b Flintoff 6R. Ponting b Broad 38M. Hussey c Collingwood b Swann 27M. Clarke not out 125M. North b Swann 6B. Haddin not out 80Extras: (6lb, 4b, 4nb) 14TOTAL: (for five wickets) 313

Overs: 86.

Fall of wickets: 1-17, 2-34, 3-78, 4-120, 5-128.

Still to bat: Mitchell Johnson, Nathan Hauritz, Peter Siddle, Ben Hilfenhaus.

Bowling: Anderson 18-3-81-0, Flintoff 17-3-49-2 (4nb), Onions 9-0-50-0, Broad 13-3-32-1, Swann 23-3-62-2, Collingwood 6-1-29-0.

Toss: England.

Umpires: Rudi Koertzen, South Africa, and Billy Doctrove, Dominica.