Tottenham boss Andre Villas-Boas admitted his side had paid a "heavy price" for a woeful performance.
The Portuguese may be under a bit of pressure after the north London side's second defeat in a row - following a 1-0 loss at home to Newcastle before the international break.
But while Tottenham came away from that game cursing their luck after a phenomenal performance from Magpies goalkeeper Tim Krul, they were outclassed in every department by City here.
"It's difficult to take," said the former Chelsea manager.
"I thought we had a very, very good reaction to the goal suffered. That's probably the only positive of the game we have is the moment we suffered - the first 20 minutes before they scored the second goal.
"It's not a lot to look for, everything went bad for us. From being one of the best defences in the country to suffering six goals.
"City were excellent, we were extremely poor and we paid a heavy price.
"From the moment we suffer the 4-0 we weren't mentally playing the game.
"We have high expectations to do well and because of those expectations, to see us 4-0 down after 51 minutes, that mentally takes us very, very down."
