City are unbeaten in 27 games and their run of 20 successive victories in all competitions is a record for an English top-flight side.

The City boss said: "It is so difficult. Twenty in this period, in this era, with this situation around the world – to be able to do 20 is maybe one of the greatest achievements we have done together in our careers.

"That doesn't mean we will win titles but we have not had one week's rest in three months. A game every three days, with the Covid situation, injury situations – to make this winning run shows mental strength."

City were not at their fluid best and were made to dig deep for their latest victory by the hard-working Hammers.

Goals in each half from defenders Ruben Dias and John Stones, either side of a Michail Antonio equaliser, ultimately proved the key contributions.

Guardiola said: "We didn't paint something nice but there are many of these games during the season.

"It was obvious to every person who saw the game it was really tough. The opposition is incredible, well composed.

"So, a big compliment to West Ham. After 26 fixtures they were in the Champions League positions. They have everything.

"It was a really tough game but that is good for us for the coming games, to realise what is going to happen."

West Ham, who had been fourth going into the game, almost snatched a late point when Issa Diop headed wide.

Manager David Moyes hailed the performance although he was not prepared to make any promises about Champions League football, and even tried to play down rising expectations.

He said: "We came to the best team in the country, probably the best team in Europe, and we gave them a really good game. We were always in the game.

"You need to take the moments and we just didn't take the moment at the end, but if we play like that until the end of the season, we will give ourselves a great chance of being up there.

"If we continue to improve, the players will give themselves a good chance of finishing in the top half.

"I am really disappointed we didn't get a point, it was a terrific performance."

The Hammers could have a goalkeeping problem. First choice Lukasz Fabianski missed the game through injury and his replacement Darren Randolph began to struggle as the game went on.

Moyes said: "Darren Randolph has only just come back. He had a bit of a thigh injury and he was only back in training a week or two, and he just felt it again.

"Lukasz picked up a minor injury in training when one of the players accidentally stepped on his arm."