There was a collective intake of breath in the stands and a string of worried faces in the dugout as Wales captain Ashley Williams lay flat on the turf in the closing stages of their Euro 2016 victory over Northern Ireland.
Williams collided heavily with a team mate as the seconds ticked away at the Parc des Princes with Wales leading 1-0 and a place in the quarter-finals within touching distance.
Substitute James Collins was readied to enter the fray but Williams insisted he would stay on the field.
It was exactly what you would expect from a player who had featured in every minute of Wales's European Championship, from the qualifying campaign through to the tournament finals.
Gareth Bale may be Wales's star attraction but Williams is their leader and he boasts a formidable appetite for battle.
The Swansea City centre back was pictured celebrating after the final whistle with his arm in a sling and there were fears he would miss Friday's quarter-final clash against Belgium in Lille.
Instead, his fitness was confirmed when he returned to training on Tuesday, one day ahead of schedule.
That was typical for a player who has made more Premier League appearances for his club since 2011 than anyone else in the English top flight.
Williams is one of the sport's great scrappers and his career has been as far away as one could imagine from the image of the pampered Premier League player whose livelihood was handed to them on a plate at a young age.
FOOTBALL'S SCRAP HEAP
Williams had to claw his way up through the game's lower ranks having been dumped on football's scrap heap at the age of 16 when he was released by West Bromwich Albion.
He was playing for non-league Hednesford Town at 19 and left fourth-tier Stockport County four years later to join Swansea, who were then going for promotion in the division above.
It was during this early part of his career that the English-born Williams started on his journey to becoming Wales's defensive linchpin.
By chance, former Wales youth coach Brian Flynn went to watch their current goalkeeper Wayne Hennessey, who was then on loan at Stockport.
"He liked me during the game and recognised that I had a Welsh surname," Williams said ahead of their group-stage match against England.
A Welsh grandfather on his mother's side meant Williams would be eligible to play for Wales and a phone call from then manager John Toshack sealed the deal.
England's loss was Wales's gain.
What would Roy Hodgson's forlorn side have given for Williams's assured presence as England came into Euro 2016 with a makeshift centre back pairing and exited with their tails between their legs after an embarrassing 2-1 defeat to Iceland?
Former England centre back Rio Ferdinand is certainly a fan. "How one of the top four teams haven't signed Ashley Williams amazes me," he said towards the end of last season.
With Williams at the heart of their defence, Wales have shut out Russia and Northern Ireland in their last two games at Euro 2016 and a third successive clean sheet could see them reach the semi-finals of a major tournament for the first time.
Should they do this, the man hailed as Wales's 'Mr Indestructible' might find himself in high demand.