AS Simon Griffin sat on the substitutes’ bench desperate to join in the rugby match in front of him, he had no clue of what was in store.

Within minutes of joining the action for Bicester Rugby Club, he was knocked unconscious, suffered a seizure and rugby tackled a friend’s mum.

Colleagues were so worried they called Thames Valley & Chiltern Air Ambulance Trust to the Chipping Norton rugby pitch.

Now club president John Deeley has hosted a lunch to raise £2,000 for the ambulance charity, which relies solely on donations.

Oxford University sports administrator Mr Griffin said: “I was running around trying to prove my worth, attempting to tackle a little too hard maybe.

“Then I woke up in my hospital bed in the A&E of the John Radcliffe Hospital.

“For me it was almost instant but I had lost about four hours.

“One minute I was playing, the next I was waking up in hospital.”

He said: “According to players and supporters I got my head the wrong side of a tackle or was knocked competing at a ruck.

“I had a seizure due to the impact and apparently became very aggressive. I had to be restrained as I had got up and rugby tackled my friend’s mum who had been caring for me.

“I heard later one of the paramedics then tackled me.

“According to my coach he thinks I was still playing out the game in my head as I was making comments like ‘come on lads’ and kicking my legs and arms.”

The 26-year-old was kept in overnight for observation at the John Radcliffe and, after head and neck scans, was given the all-clear two weeks later.

He said: “The coach said if I had the same strength and made tackles like I did on my friend’s mum normally, I would be a hell of a player, but alas I don’t know where it came from.”

Mr Griffin said he is indebted to the air ambulance. He said: “I was staggered when I found out it is not funded like the police and that each trip costs over £1,200.

Sarah Williamson, fundraising manager for TVCAA, said: “All the team at Thames Valley and Chiltern Air Ambulance are extremely grateful to Simon and the club for their generous support.”