Steve Smith forced to retire hurt after being struck on back of the head by Jofra Archer at Lord's

The England seamer hit the Australian on the left forearm and then the gloves with deliveries which reached a top speed of 96.1 miles per hour, before catching Smith on the back of the neck with another bouncer timed at 92.4mph

Steve Smith was forced to retire hurt on the fourth afternoon of the second Ashes Test at Lord's after being sickeningly struck on the back of the head by a Jofra Archer bouncer.

Smith was batting serenely and heading towards another century when Archer began a barrage of short-pitched bowling midway through the second session of the day.

The England seamer hit the Australian on the left forearm and then the gloves with deliveries which reached a top speed of 96.1 miles per hour, before catching Smith on the back of the neck with another bouncer timed at 92.4mph.

Smith was immediately floored by the blow and there was genuine concern for his wellbeing.

A hush descended over Lord's when the batsman hit the turf, with the incident immediately bringing back memories of the tragic Phil Hughes, who died after being hit in a similar part of the body during a Sheffield Shield match in 2014.

Since then, helmet manufacturers have developed extra protection for batsmen in the neck region, but Smith did not appear to be wearing the additional kit on Saturday.

^{Steve Smith receives treatment at the crease}

He was seen to at the wicket for several minutes before being encouraged to leave the field for further assessment.

After undergoing tests in the dressing room, however, Smith remarkably returned 46 minutes after being hit, after Peter Siddle edged behind to Chris Woakes.

Cricket Australia issued a statement which read: "Steve was hit on the neck below the left ear. 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."

He subsequently launched his second ball back over mid-on for four and then guided his third delivery through extra cover for another boundary.

His innings was brought to an end, however, when he offered no shot to Woakes and was trapped lbw.