England overcome poor conditions to grab 2-1 series win over Proteas
Mendy made his return after a seven-month injury layoff.
Supporters invaded the pitch on the final whistle, despite appeals from the club not to do so and efforts from stewards and security to stop them encroaching onto the pitch.
But Mendy, who had come on as a 75th-minute substitute for his first appearance after seven months out with a cruciate knee ligament injury, was in no hurry to leave the field and was seen jumping up and down with dozens of supporters.
He was eventually freed by security and, within minutes of the final whistle, was sending out images of the scenes on his social media accounts.
The English Football Association are still likely to take action against City following the crowd scenes but, for Mendy and his hopes of being fully fit for the World Cup which starts in 53 days, his return was a welcome one.
The 23-year-old France left-back, signed from Monaco last year, is also now eligible to receive a Premier League title winner’s medal from City after he made his fifth appearance of the season for Pep Guardiola’s side.
Mendy, who became a popular figure with City supporters thanks to his social media profile, played in four league games for City prior to injuring his knee in a victory against Crystal Palace in September.
But his return to action will strengthen his hopes of being available for the French squad for the World Cup.
Guardiola also had encouragement for England manager Gareth Southgate over the fitness of defender John Stones, who has not played for City since suffering a thigh injury on international duty last month.
“I think he will be fine for the World Cup,” said Guardiola. “It’s getting better.”
Download our app and read this and other great stories on the move. Available for Android and iOS.