LONDON: Australia batsman Steve Smith just missed his third Ashes hundred in as many innings after returning following a sickening blow to the neck from a Jofra Archer bouncer on the fourth day of the second Test against England at Lord's on Saturday.

Smith's 92 was the centrepiece of Australia's 250 all out in reply to England's first innings 258.

The star batsman had made 80 when he was felled by a bouncer from World Cup-winner Archer, making his Test debut, timed at 92.4 mph.

The ball struck him on the side of the neck and head.

Smith, fell face forward onto the ground. He was wearing a helmet without the additional neck protection that was introduced following the death of Phillip Hughes after his former Australia team-mate was hit by a bouncer in a 2014 domestic Sheffield Shield match in Sydney.

Smith, who had marked his comeback Test following a 12-month ball-tampering ban, with innings of 144 and 142 in Australia's 251-run win in the series opener at Edgbaston last week, received several minutes of on-field treatment involving both teams' medical staff.

He got to his feet but eventually retired hurt, with Smith receiving a generous round of applause as he walked back into the pavilion.

Australia were then 203-6.

Archer had previously struck Smith, then on 70, on his unprotected forearm with another bouncer during a fiery eight-over spell that cost 31 runs.

And it was that injury, not the blow to the neck, which an Australia team spokesman said prevented Smith from fielding at the start of England's second innings.

"Steve Smith is off the field because of his sore left forearm and has been taken for a precautionary X-ray of that arm after being struck there during his innings," the spokesman said.

Earlier, Smith' resumed his innings as soon as he could when Peter Siddle's exit left Australia 218-7.

From the second and third balls he faced on his return after 46 minutes off the field, Smith hit two fours off Chris Woakes -- a slammed shot over mid-on followed by a backfoot drive through the covers.

But on 92, facing his ninth ball, Smith shouldered arms to a Woakes delivery that nipped back and was plumb lbw to leave Australia 234-8.

In total, he faced 161 balls including 14 fours.

Smith turned towards the pavilion, signalling that he was reviewing umpire Chris Gaffaney's decision almost as an after-thought before replays confirmed his dismissal.

This series, the first of the ICC's new World Test Championship, has seen the introduction of concussion protocols designed to allow injured batsmen to be replaced by a substitute -- previously restricted to fielding duty alone.

- Smith assessed on pitch -

But the Australia spokesman insisted Smith's health had not been put at undue risk by letting him resume his innings.

"Steve was hit on the neck below the left ear," the spokesman said.

"He was assessed lying on the pitch at the instructions of team doctor Richard Saw.

"Dr Saw made the precautionary decision to remove Steve from the field of play to have him further assessed under Cricket Australia's head impact protocol.

"Steve then passed his assessments and will now be monitored on an ongoing basis, as is routine."

Stuart Broad, leading the attack in the absence of the injured James Anderson, England's all-time leading wicket-taker, took 4-65 in 27.3 overs and Woakes 3-61 in 19.

Archer finished with figures of 2-59 in 29.

Australia had resumed Saturday on 80-4 with Smith 12 not out and Matthew Wade, who also made a hundred at Edgbaston, unbeaten on nought.

Broad soon had Wade caught low down by Rory Burns at third slip for an innings of six that took 45 balls.

Smith, amid some typically extravagant 'leaves', completed his fifty when he lofted spinner Jack Leach over long-on for four.—AFP