England's batsmen were suddenly plunged into a fight for survival at Lord's today after openers Andrew Strauss and Alastair Cook had given them a dream start to the First npower Test against South Africa.

The two left-handers put together a stand of 114 and looked set to make visiting captain Graeme Smith regret his decision to bowl. But then an error from Australian umpire Daryl Harper parted the pair - and put some fire back into a pace attack that had huffed and puffed without success on a slow pitch for three hours.

Strauss fell lbw to Morne Morkel but the ball pitched outside leg stump and Harper should have turned down the appeal. That was all the South Africans needed, however, to get cracking.

Dale Steyn easily got the better of Michael Vaughan (two) to knock back the England captain's off stump and then Cook (60) was startled by a lifting delivery from Morkel and could only loop a gentle catch into the slip cordon.

Vaughan's men had lost three wickets for three runs in the space of 13 balls and, far from sitting pretty, found themselves up against it at 117 for three.

It could have been worse, though, because Kevin Pietersen - playing his first Test against the country of his birth - got off the mark with a suicidal single against Steyn and only survived because Makhaya Ntini missed the target from mid-on.

Minutes later, Pietersen was hit on the helmet by Steyn's bouncer, leaving both him and England shaken. But he and Bell then steadied the ship, with the latter looking in particularly fluent form, as England reached 163 for three at tea.

Vaughan admitted he, too, would have chosen to bowl first. In the event, though, the pitch did less than Smith was hoping - and his pacemen failed to make the openers play enough at the new ball.

All eyes were on Steyn at the start of play because the 25-year-old has turned himself into world cricket's hottest fast bowling property.

Here, South Africa's spearhead soon managed to hit 90mph but looked visibly deflated once the new ball refused to gain any significant height, never mind zip, on its way through to keeper Mark Boucher. In fact, it was Ntini who extracted more lift to surprise both Cook and Strauss.

Despite an economical start, which yielded just three singles in six overs, Smith was already getting anxious for a breakthrough and his determination to try to make things happen became apparent when Morkel replaced Steyn at the Nursery End after half an hour.

Morkel is taller than his two main pace partners, and a lot less experienced with only six Test appearances before this one. But the 90mph barrier is no problem to him, either, and a hint of late swing kept England's openers on their guard until opportunities to attack began to present themselves.

When Ntini tried to unsettle Strauss with a shorter delivery, the ball simply sat up invitingly for the Middlesex man to pull the game's first boundary midway through the eighth over. Then Morkel gave Cook so much width that the junior opener did well to reach it, never mind flash a four to third man.

Another cut, this time in front of square, brought Cook a second boundary, off Ntini, and there was more joy for England once Morkel switched to the Pavilion End. Four byes went swinging down the leg side, out of Boucher's reach, before a wide half-volley was steered away by Cook.

Although Ian Bell and Paul Collingwood were the real strugglers against the Kiwis earlier this summer, Cook managed only 114 runs in four innings and is without a Test century so far this year after also drawing a blank in New Zealand. But he has been a terrific find, with seven hundreds in 30 games since stepping into the spot sadly vacated by Marcus Trescothick, and noone should doubt his right to a place.

Here, Cook and Strauss were soon confronted by Jacques Kallis as Smith continued to chop and change his pacemen. But a close shave or two was the nearest South Africa came to drawing blood before lunch - and Ntini's unsuccessful lbw shout against Cook, with the total 59, proved to be the only real appeal of the first session.

If the tourists were disappointed by the pitch, and their own lukewarm efforts on it this morning, though, their sense of frustration increased considerably after the break as Cook twice edged Ntini out of Kallis's reach at second slip before completing his 92-ball half-century.

There was nothing flirty, however, about Strauss's square drive against Steyn. And when he straight drove

Ntini for another four, the pair were able to celebrate their second century stand at the top of the innings. Two months ago they put on 121 against New Zealand at Lord's but this effort was better still in terms of importance.

It might also have been bigger but for umpire Harper's failure to detect that Morkel's delivery pitched outside leg stump before thudding into Strauss's pad.

One wicket was all it needed, though, to put the fire back into South Africa and the game changed dramatically when Vaughan and Cook were dismissed before Bell and Pietersen led a recovery.