City paid the price for failing to kill off Boro at the Etihad Stadium on Saturday as Marten de Roon snatched a 1-1 draw with an injury-time header.
The result cost them top spot in the Premier League and punctured the feelgood factor created by Tuesday's exhilarating Champions League victory over Barcelona.
City only had themselves to blame after spurning numerous chances throughout the game
They had 18 shots in the first half alone but did not take the lead until Sergio Aguero registered his 150th City goal - and his 14th of the campaign - in the 43rd minute.
"It is disappointing," said goalkeeper Bravo, who could do little to keep out a thunderous header by De Roon after the Dutchman latched onto Stewart Downing's pinpoint cross
"We leave with a bad feeling.
"We had been creating chances and playing good but we didn't get the result
We got possession and created lots of chances but we didn't score many goals.
"It is very hard to play against teams like Middlesbrough but we need to improve both in attack and defence.
"There is never an easy game, every game is tough, but we want to beat every team either at home and away
We have to keep working."
It was City's third consecutive home draw in the Premier League after also being frustrated by Everton and Southampton.
It did seem they were affected by their Champions League exertions as their intensity notably dropped in the second half.
They had also started the game sluggishly but Boro, seemingly anticipating an onslaught, defended deep and allowed the hosts to take charge.
It took them some time to prise a way through as Victor Valdes produced good saves to deny Aleksandar Kolarov, David Silva and Aguero, among other City opportunities, but the result seemed a formality at half-time.
Things changed as Boro began to assert themselves more after the break and force errors, but Aguero and Kevin De Bruyne both spurned gilt-edged chances to secure victory late on.
That came back to haunt them as midfielder De Roon, a £12million summer signing from Atalanta, grabbed his first goal for the club.
It was another notable result for promoted Boro coming after a draw at Arsenal and victory over Bournemouth.
De Roon said: "I don't believe it yet, it was an incredible moment, and against Man City where normally it is really difficult to get points.
"At the end to score for 1-1, it feels like a victory
If you are 90 minutes 1-0 behind and you make it in the last minute against Man City, it is a really welcome point."
Source : PA
Source: PA