Manchester - Pep Guardiola criticised his Manchester City defence after they allowed Wilfried Zaha too much space in setting up Crystal Palace' late equaliser in their 2-2 Premier League draw on Saturday.
Two goals in the final eight minutes from Sergio Aguero appeared to have secured all three points for Guardiola's side until Zaha took control.
The Palace winger was sent racing clear by James McCarthy and his cross was turned into his own goal by Fernandinho, under pressure from Connor Wickham.
It left Guardiola bemoaning his side's poor defending as they struggled for the second successive season at home to Roy Hodgson's team, who came away with a 3-2 win last term.
The dropped points leave the champions 13 points off leaders Liverpool having played two games more.
"Last season, when they beat us here, it was the same," said Guardiola. "They had three shots on target, they scored three. This season, the same.
"The goal, we have to avoid it, we just can't allow Zaha to run. It was a decision, the concentration was there, but it was a wrong decision.
"We're going to solve it and improve it because in that situation, we cannot let them run on the counter-attack."
Aguero's brace took his career tally for the club to a 251 goals since his arrival in 2011.
After 82 minutes, substitute Gabriel Jesus floated in a magnificent cross towards the far post for Aguero, who slid in ahead of his marker to volley left-footed into the open net.
His second came just five minutes later.
This time it was full-back Benjamin Mendy who set up the striker with a perfect left-wing cross which Aguero met with a downward header into the far corner of the Palace goal.
Uncertain defending from that last-minute counter-attack found the home defence lacking, as had been the case when Tosun headed them into a shock lead, against the run of play, on 38 minutes.
The goal came from a McCarthy corner and underlined the defensive shortcomings that have seen Guardiola's team keep just two clean sheets in their last 13 games.
The ball floated to the centre of the area where Gary Cahill rose impressively, above John Stones, and headed towards the far post where Tosun had been left unmarked by Bernardo Silva and Ilkay Gundogan gravitating towards the ball.
Tosun, making his first start since joining Palace on loan from Everton, was left with the simple task of steering a header past Ederson in the home goal.
The situation could have worsened considerably for City moments later when Tosun chased a long through ball and easily rounded Ederson, who had wandered 30 yards from his net, only to have his goal ruled out for offside.
But, otherwise, City's dominance was near-total with visiting keeper Vicente Guaita in inspired form, most notably when tipping a Bernardo Silva drive over his bar just before the interval.
City were also awarded a penalty, overturned by VAR after replays showed defender Jairo Riedewald had kicked the ball onto his own hand from a Joao Cancelo cross, before the late drama.