James Lawton on the Ashes: Pressure is now on Kevin Pietersen to reassure a suddenly nervy nation

The Poms had been found guilty of the most outrageous act of presumption

Kevin Pietersen plays straight in England’s second innings yesterday (Getty Images)

The beauty of winning any Test match – let alone the one here which after just two days is shaping up as both great and astonishing – is that it takes more than one burst of the kind of fortitude and brilliance 19-year-old Ashton Agar brought to the old battleground.

You also have to have the reserves of nerve and patience which England's captain, Alastair Cook, had to demand from himself and his most gifted batsman, Kevin Pietersen, after the young Australian had created a record-breaking momentum all of his own.

Agar, reared in Victoria but of Sri Lankan heritage and picked not as a batsman but yet another of the legion of tenderfoot spinners asked to fill the vacuum created by the departure of Shane Warne, scored 98 unprecedented runs of mostly impeccable technique and superb imagination from the No 11 position.

Much more importantly, he gave the most dramatic evidence so far that claims the home-and-away Ashes series will result in a 10-match whitewash of his team reside mostly in the over-heated imaginations of former England captains like Sir Ian Botham and Andrew Flintoff.

The transformation Agar worked in the company of his senior team-mate Phil Hughes – they put on 163 for the last wicket – was breathtaking, a great and unforgettable phenomenon in the toughest, most demanding terrain of their game.

It also invited an England team which raced to the top of the Test rankings not so long ago, then threw away the achievement partly through an eruption of adolescent civil war in the dressing room, to stand up finally and play some serious cricket at the outset of this Ashes series they have been widely tipped to dominate from the word go.

So far it just hasn't happened. The tough old bowling warrior Peter Siddle, also from Victoria, stole the first day with a five-wicket haul which came as a reminder of the hat-trick he worked against England at The Gabba at the start of the 2010-11 series.

Siddle gave his team more than a sniff of blood here on Wednesday. Today Agar was the second part of a one-two punch combination which left England fans stunned and their Australian counterparts exulting. The Poms, cried their tormentors, had been found guilty of the most outrageous acts of presumption in the history of big-time sport. England might prevail, it was true, but by 10-0? What kind of cigarettes had Botham and Flintoff been smoking?

It was a reasonable question when Agar unfurled his precocious batting gifts, but then it is also true that, despite the youngster's record of three half-centuries in 10 first-class matches, there could be no reason to believe he would hit quite such majestic levels.

The sadness was that after hitting 12 fours and two sixes – all of them with a beautiful and at times almost nonchalant authority – the first clear signs of vulnerability came only when he drew to within two runs of his century. Then, there were hints that he might just not have been entirely mis-cast in the No 11 position. Suddenly he seemed aware that he had marched into an extraordinary position in cricket history and that a 100 would mark the perfect celebration.

Stuart Broad, forced into the lightest action because of injury, has never been squeamish in the matter of exploiting signs of weakness and he duly applied a little heat. Agar, who had been wielding his bat so deftly and with so much certainty, reached out for his century with none of the precision he had been almost routinely showing against bowlers of the quality of Jimmy Anderson and Graeme Swann, the latter dashing in from deep midwicket to make the catch.

That left England trailing by 65 after scoring 215 in the first innings – staggeringly, when you recalled that when Agar came to the wicket Australia had crumbled to a ruinous 117 for 9 – and with a huge requirement to check momentum which had swung so hugely behind their opponents.

This was an extremely desirable development when Cook sat down with his shell-shocked troops, but then soon enough it was a case of basic survival.

The excellent Mitchell Starc, a left- arm fast swing bowler who moves with the smooth action of the most promising of candidates in a most demanding discipline, augmented the work of his young team-mate with two superb strikes. One sent back Joe Root, the other had the cornerstone man Jonathan Trott lbw. There was some dispute about this when it went to review, but, all video deliberations apart, it was a beautiful delivery which surely sent a chill through the English dressing room.

England were 11 for 2 and they had to deal with a deficit that seemed to grow more formidable each time Cook and his new partner Pietersen displayed something less than the confidence that accompanies their most prolific periods of run-hoarding. Agar was called again to the front line, this time with a ball in his hand, and caused both batsmen moments of discomfort.

By the finish, though, England had nosed into a 15-run lead. It had been hard and not always convincing work but there was the supreme virtue of superior application.

Pietersen was easy to see as the decisive counter-weight to the extraordinary break-out of Agar. His speed of accumulation and the ease with which he can slip into a mood of untrammelled virtuosity certainly brought a shadow to the Australians efforts in the evening sunlight. At least the promise of it did.

As it was, Pietersen produced a couple of boundaries of absolute facility, and at 37 was plainly England's best chance of putting down a team which has, on two straight days, had the temerity to suggest they might just win what is supposed to be one of the most one-sided battles in Ashes history.

Siddle and Agar, Hughes and Starc maybe an unfamiliar, even unlikely cast of heroes, but they have announced that they are dangerous and it is Pietersen's job today to provide a degree of reassurance to a suddenly anxious nation. It will probably take a least a century – and a good one too.

Timeline: How the second day unfolded at Trent Bridge

10.24: England injury update

England's fast bowler Stuart Broad, who bruised his arm on the first day, will take to the field and is expected to bowl. Relief for the hosts, but will he be at his best?

11.29: 50 for Smith: Aus 108-4

Smith drives through the covers for four off Swann. Smith is the first batsman to make a half-century in this Test.

11.32: Wicket: Smith c Prior b Anderson 53. Aus 108-5

Early breakthrough: Smith aims an airy drive at Anderson's full delivery and is caught behind.

11.37: Wicket: Haddin b Swann 1. Aus 113-6

Stunning ball by the in-form Swann. His delivery pitches well outside off stump but spins back sharply and clean bowls Haddin. England gain momentum.

11.43: Wicket: Siddle c Prior b Anderson 1. Aus 114-7

Top wicketkeeping: Siddle nicks Anderson's delivery and Prior takes a brilliant one-handed catch.

11.47: Dropped catch: Aus 114-7

Anderson draws new man Starc into edging straight to Swann at second slip. It's a regulation catch but he fumbles it – much to his own disgust.

11.50: Wicket: Starc c Prior b Anderson 0. Aus 114-8

Anderson, the master of the art of reverse-swing bowling, finally gets his man to bring up superb figures of 5-39.

11.58: Wicket: Pattinson lbw Swann 2. Aus 117-9

Swann traps Pattinson lbw. Agar is next in. England will soon be batting again, surely?

1.09: 50 up for Agar: Aus 192-9

Agar is proving to be a very capable batsman, becoming the first Test debutant No 11 to score 50.

1.14: 50 up for Hughes: Aus 206-9

Brilliant moment for the resolute Australia batsmen. After Smith and Agar, Hughes – who has been stoic at the crease – brings up his half-century. How can England break this stand?

2.37: Test record: Aus 271/9

Hughes and Agar bring up their 150-run partnership before going on to set a new Test record for a 10th-wicket partnership.

2.53: Wicket: Agar c Swann b Broad 98. Aus 280 all out

The Ashton Agar Show ends. The 19-year-old debutant, who played like a top-order batsman, is caught just short of his ton.

3.10: Umpire review: Eng 3-0

Nervy start to England's second innings. Umpire turns down Starc's lbw appeal against Root. Aussies ask for referral which shows ball clipping leg stump. Umpire's call. Not out.

3.36: Wicket: Root c Haddin b Starc 5. Eng 11-1

Terrible start. The Yorkshireman nicks Starc's delivery and Haddin happily takes the catch.

3.40: Wicket: Trott lbw b Starc 0. Eng 11-2

Trott trapped in front, umpire says not out. Australia refer it. Replay shows it's plumb despite claims Trott got a nick.

4.01: Hat-trick ball: Eng 11-2

Third hat-trick ball of the match so far... but Starc bowls a poor delivery, judged to be a wide. England desperately need some stability at the crease now.

5.49: Hosts lead by two runs: Eng 67-2

England make very slow progress as captain Cook cover drives and moves England into the lead.

6.33: Stumps: Eng 80-2

An absorbing day comes to a close. A slow final session sees Cook (37) and Pietersen (35) survive as England build a 15-run lead.Giles Lucas