Sergio Aguero had put City ahead with his 150th goal for the club just before the interval but the hosts failed to make the most of numerous other chances.

City registered 18 shots to Boro's none in the first half alone but their intensity dropped after the break and their midweek Champions League exertions against Barcelona may ultimately have caught up with them.

Manager Guardiola said: "In the second half we didn't play like in the first half but I didn't think we played badly.

"I think they had one chance in the beginning of the second half and one in the last minute.

"Like against Everton and Southampton, when you see what the opponents did in all three games at home and we dropped six points, they arrived maybe four or five times in our box. When you play the way we want to play, they had 10 players in the box for 90 minutes.

"We created enough chances, we attacked really well and we controlled the counter-attacks but when you arrive in the last minutes just 1-0, everything can happen.

"If we talk about the performance after a demanding game last Tuesday, how we started, moving the ball right and left, maybe in the last minutes the team can be tired.

"But if we had scored the second goal, the chance for Sergio or Kevin (De Bruyne), the game was over."

Aguero spurned a fine opportunity to double City's lead when he shot over with five minutes remaining.

Asked about the Argentinian's landmark goal in the 43rd minute, Guardiola said: "Big congratulations. It is a huge mark, it is a lot of goals. I only scored 11 in my career!"

Guardiola was unwilling to discuss the tactics of Middlesbrough, who played very defensively in the first half.

Asked if he was impressed by Boro's gameplan, he said: "No I am not... I am not here to talk about the performance of my opponents. (Aitor Karanka) is their coach and knows better than me how they want to play."

Boro boss Karanka was pleased with another valuable away point a fortnight after drawing 0-0 at Arsenal.

He said: "Arsenal and Man City have amazing squads, so for us to compete against them at their stadiums is good for us.

"This was much more difficult because against Arsenal we didn't concede a goal and we created a few chances.

"Today we went onto the pitch and showed them too much respect. In the first half we just tried to defend and when you are against big teams and you just think you are going to defend, you concede a goal. For that reason at half-time I told them we had to try to play."

Karanka admitted De Roon's goal was a sweet moment.

He said: "I felt amazing because I had 11 players fighting 90 minutes on the pitch and I know how important it is to them to take this point or the one we took at Arsenal.

"This is the way to keep going, playing against these teams and showing we can compete."