City looked set to cut Chelsea’s lead at the top of the Barclays Premier League to one point as they opened up a 2-0 first-half lead.
But the Clarets fought back after the break and snatched a surprising point as Ashley Barnes levelled with a stunning strike nine minutes from time.
The result left City three points behind Chelsea but Pellegrini refused to read too much into the performance, which came just two days after a draining win at West Brom.
Pellegrini said: “Maybe winning 2-0 we thought the game was over but until the last whistle the game is never finished. It is clear we couldn’t keep the same intensity in the second half.
“The first goal was very important for them because they improved a lot and had a lot of trust.
“It is difficult for all the teams – especially our team because we played on a very heavy pitch against West Bromwich in the last game – to keep the same pace in the second half.”
David Silva and Fernandinho were on target for City in a dominant first half. Silva’s well-worked 23rd-minute opener came when Samir Nasri fed Jesus Navas down the right. Navas turned the ball back inside to find Silva and he had the space to turn and drill home a low shot for his fourth goal in three appearances.
City doubled the lead ten minutes later after more patient approach play. Nasri looked to have been crowded out on the edge of the area but Fernandinho had more space behind him and took a touch before lashing home a powerful curling shot off the underside of the bar.
But the game changed two minutes after the restart when George Boyd – despite suspicions of offside – appeared to divert in a Danny Ings cross- cum-shot. The late leveller came after a free-kick was lofted into the area and Burnley’s players managed to get all the crucial touches before Barnes smashed into the top corner.
Pellegrini added: “Football has a lot of things that can decide that score. We played well in the first half, we were 2-0 up but in the second minute of the second half Burnley score a clear offside goal. After that they scored their second from a rebound. But I am not saying we are unfortunate. I am saying, in football, just two balls can decide the score.”
Pellegrini downplayed the significance of the result in terms of the title race, saying: “Of course, after you are winning 2-0, it is more disappointing to lose those two points but we have all the second round [of fixtures] to see who will be the best team.”
For Burnley the point was a valuable one in their battle against relegation. The Clarets have shown their fighting qualities in recent weeks and manager Sean Dyche was pleased with their attitude throughout.
He said: “We went in at half-time intact in terms of how we were playing. I reminded the players of that and we put down a marker by getting the first goal and building on top of that.
“Then, not only getting the goal so early but the relentless nature of the performance after that, I thought the quality was high, the endeavour was high, I thought the organisation was high. I was very pleased with everything. I keep reading about struggling Burnley. But I do know what the expectation was – we had no chance at all.
“So I can’t work out why I keep reading about struggling Burnley, because we’re not struggling. I am aware of the league table but when you look at how the team is performing, we’re not actually struggling, we’re actually playing really well. I’m very intrigued to know where the journey is going.”
There was an element of confusion over the goal credited to Boyd. The Scot appeared to be in an offside position when the ball reached him but there was some debate over whether he actually touched it.
Dyche said: “I’ve no clue and I’m not interested. I know it went in, and that was my main concern. I actually haven’t seen it. Someone said it is offside. All I’d say is, a scratch of luck when you’re Burnley Football Club – we don’t always get that so we’ll take it gladly. Everyone needs that whatever level you’re at.”