ADELAIDE (Australia) (AFP) - Alastair Cook again proved to be an immovable force, blunting Australias bowlers to put England in a commanding position in the second Test at the Adelaide Oval on Saturday. The frazzled Australians endured a long hot day of toil in the field for scant reward as Cook continued to be the marathon man of the Ashes series, scoring his second century. England cruised past Australias below-par first innings total of 245 some 23 overs before stumps and finished the sweltering second day at 317 for two, a lead of 72. Cook followed up his unbeaten 235 in Brisbane to end the day on 136 with Kevin Pietersen, not out on 85, threatening to unleash a big score on Sundays third day. The pair have so far put on 141 runs together for the third wicket. Vice-captain Cook, displaying immense powers of concentration, has amassed 438 runs in three innings in this series for one dismissal and has spent all but 11 overs on the field in the first seven days of the series. It was excellent conditions to bat in today, 37 degrees (Celsius) and a good wicket to bat on, Cook said. It was important to make the most of what our bowlers did yesterday. It was fantastic effort to dismiss them for 245. We are in a really good position now but its only day two so theres a lot of cricket left as we showed last week you can fight back. The Essex left-hander helped himself to four with a cut off ineffectual spinner Xavier Doherty to reach his ton, his third against Australia. Cook has now scored 15 Test centuries before the age of 26, equalling the achievement of Australian legend Don Bradman. Only Indias Sachin Tendulkar, the leading Test run-scorer of all time, managed more, reaching three figures 19 times before his 26th birthday. The only time Cook looked in trouble came when he needed a review on 64 to survive after he was given out caught behind attempting to hook Peter Siddle in the 43rd over. Replays showed that the ball hit Cooks arm rather than his bat and umpire Marais Erasmus reversed his decision. England are in a very good position, but the important thing for us is to make sure we stay in the fight, Australian wicketkeeper Brad Haddin said. Test cricket is never easy and we have our backs to wall and were in for a real fight. Australia had early joy with the wicket of skipper Andrew Strauss in the days opening over, but apart from Jonathan Trotts dismissal for 78 before tea it was unquestionably Englands day. Cook and Trott put on 173 runs for the second wicket to kill off Australias hopes of containing Englands innings lead. Trott had three lives before his luck finally ran out in the 49th over when he flicked a Ryan Harris lifter to a diving Michael Clarke at midwicket. The number three batsman had looked on course for his third century in as many Ashes Tests after his 119 at the fifth Test at The Oval last year and 135 in Brisbane last week. Trott and Cook so far in this series have shared in partnerships totalling 502 runs after their record stand of 329 runs at the Gabba. Doherty had a chance to run Trott out on six but his throw was well wide and the batsman enjoyed more luck four runs later when Mike Hussey dropped him in the gully off Doug Bollinger. Trott got his third life on 76 when wicketkeeper Brad Haddin fumbled a high two-handed chance down the leg-side off a Harris bouncer to continue the home sides wretched fielding in the series. The normally reliable Australians put down five catches in the drawn Test in Brisbane. The day started well for Australia when Bollinger removed Strauss with the third ball of the day as the England skipper inexplicably offered no shot to the left-armer and was bowled for one. Australia were rattled out for 245 after winning the toss on Fridays opening day, their worst performance in the first innings at Adelaide since being skittled by the West Indies for 213 in 1993. England have now amassed 834 runs in the last two innings of the series for the loss of just three wickets. SCOREBOARD AUSTRALIA, first innings: 245 (M Hussey 93, B Haddin 56, S Watson 51; J Anderson 4-51): ENGLAND, first innings (overnight 1-0): A Strauss b Bollinger 1 A Cook not out 136 J Trott c Clarke b Harris 78 K Pietersen not out 85 EXTRAS: (b4 lb7 w6) 17 TOTAL: (2 wkts, 89 overs) 317 Fall of wickets: 1-3 (Strauss), 2-176 (Trott) BOWLING: Harris 19-4-51-1 (1w) Bollinger 15-0-76-1 (5w) Siddle 16-3-50-0 Watson 14-5-31-0 Doherty 15-3-70-0 North 10-0-28-0 To bat: P Collingwood, I Bell, M Prior, S Broad, G Swann, S Finn, J Anderson. Toss: Australia Crowd: 34,975 Umpires: Marais Erasmus (RSA), Tony Hill (NZL) TV Umpire: Billy Doctrove (WIS) Match referee: Jeff Crowe (NZL)