A Watford fan suffered a cardiac arrest which caused the Premier League match against Chelsea to be temporarily halted on Wednesday.
Referee David Coote took both sets of players off the pitch at Vicarage Road in the 12th minute due to the medical emergency in the Graham Taylor Stand.
Medical staff from both teams raced across the pitch to assist the supporter, who was stabilised and then carried out on a stretcher to be taken to hospital.
Adam Masina was down receiving treatment when the fan appeared to be taken ill. Fellow supporters got the attention of the players, who then waved down the medical staff.
The players were off the pitch for around 25 minutes, before returning to the field for a five-minute warm-up, and the match resumed with the clock set at 12 minutes.
Watford tweeted: “The players have returned to the field in preparation of play resuming.
“Our thoughts are with the fan – who had a cardiac arrest but has now been stabilised – and all those affected.
“Thank you to the medical staff, players and fans for their quick response.”
A Chelsea statement read: “The thoughts of everyone at Chelsea Football Club are with the fan and all those affected.
“Our thanks to the medical staff here at Vicarage Road for their quick response.”
Chelsea full-back Reece James, who was absent from the squad on Wednesday, tweeted: “My prayers are with the fan needing medical attention.”