An “educated” man was stabbed while leaving a coffee shop close to Kew Gardens.
The victim, in his 50s, was taken to hospital where he remains in a stable condition.
It is understood that the man was trying to get into his car when he was attacked.
Gino Gashi, 40, a barrista at the Torellis cafe, said that a man had tried to rob his customer.
Gashi said: “The victim came in and asked for a coffee and we spoke about the Arsenal-Chelsea game.
“We spoke for about five minutes, and he left and said goodbye – we could see him at his car.
“He has a Ford Focus RS, the man could have tried to rob him for that or his wallet.