The Swans cruelly went down to a dramatic 2-1 defeat at Manchester City after Yaya Toure's last-gasp strike deflected off team-mate Kelechi Iheanacho.
A brave performance from the Swans, being led temporarily by Alan Curtis following Garry Monk's exit on Wednesday, had seen sub Bafe Gomis fire home a 90th-minute equaliser at the Etihad Stadium.
But the hosts, who had led 1-0 courtesy of Wilfried Bony's first-half header, took all three points as Toure 's curling effort took a deflection off sub Iheanacho before dropping into the far corner deep into stoppage time.
The visitors had the best chances throughout, with Wayne Routledge and Gylfi Sigurdsson being denied by Joe Hart on a number of occasions.
Despite the defeat, the Swans can take a lot of positives from their performance as they prepare for home clashes with West Ham and West Brom.
The Swans made three changes to the starting XI.
From the 3-0 defeat to Leicester City last time out, Alan Curtis - who temporarily took charge following Garry Monk's departure on Wednesday - recalled Angel Rangel and Federico Fernandez to the defence.
The other change saw Jack Cork return in midfield, with Andre Ayew leading the line up front and Wayne Routledge playing just behind the Ghanaian.
Jonjo Shelvey again missed out as he has a slight calf strain while Franck Tabanou (thigh) and Eder (ankle) remained sidelined.
Manchester City went into the game having beating Borussia Monchengladbach - pre-season opponents for the Swans in July - to top their Champions League group.
Wilfried Bony was on the scoresheet for Manuel Pellegrini's side, and the Ivorian continued to lead the attack in Sergio Aguero's absence.
MANCHESTER CITY: Joe Hart, Bacary Sagna, Eliaquim Mangala, Nicolas Otamendi, Gael Clichy, Rahaeem Sterling (Fabian Delph, ht), Fernandinho, Yaya Toure (capt), David Silva (Kevin De Bruyne, 68), Jesus Navas, Wilfried Bony (Kelechi Iheancho, 83).
SUBS: Willy Caballero, Aleksandar Kolarov, Martin Demichelis, Patrick Roberts.
SWANS: Lukasz Fabianski, Angel Rangel, Federico Fernandez, Ashley Williams (capt), Neil Taylor, Leon Britton (Jefferson Montero, 75), Jack Cork, Ki Sung-Yueng, Gylfi Sigurdsson, Wayne Routledge (Modou Barrow, 75) , Andre Ayew (Bafe Gomis, 83).
SUBS: Kristtofer Nordfeldt, Kyle Naughton, Jordi Amat, Matt Grimes.
The Swans started well at the Etihad Stadium, and carved open the first opportunity with just five minutes on the clock.
Jack Cork slipped through a pass for Wayne Routledge to run onto, and when he shrugged off Nicolas Otamendi only Joe Hart stood in his way. But the winger's low shot deflected off the legs of Hart and away from danger.
Manchester City responded ten minutes later through Wilfried Bony, but his low shot for David Silva's cross was easily collected by Lukasz Fabianski.
The Swans threatened again, and it took a fine reflex save from Hart to deny Gylfi Sigurdsson's rasping effort.
But the hosts did break the deadlock after 26 minutes.
After Jesus Navas had seen his shot headed out for a corner by Ashley Williams, Bony powered his header from the resulting delivery from close range.
The Swans, though, went in search of an immediate equaliser and they came close to doing so.
After Sigurdsson's pinpoint free-kick found Andre Ayew, the Ghanaian's header just flew over the crossbar.
That proved the last real action of the half, which - aside from the goal - was full of positives for the Swans.
HALF-TIME: Manchester City 1 Swans 0
The Swans continued their positive performance after the restart.
Sigurdsson saw his shot blocked during a scramble in a crowded box while he was denied from an angle by Hart soon after.
Inbetween those efforts, Yaya Toure saw his 25-yard free-kick padded wide by Fabianski, but it was opposing keeper Hart who remained the busiest.
The England keeper again had to be on his toes to dive across goal to tap wide a dangerous Sigurdsson free-kick, which had bounced into the box.
The Swans made a double change with 15 minutes to go as Modou Barrow and Jefferson Montero replaced Leon Britton and Routledge.
Barrow made an instant impact, with the winger being hauled down by Eliaquim Mangala to earn a free-kick, which eventually culminated in Cork seeing his shot deflected wide for a corner.
A final Swans change was made with seven minutes to go as Bafe Gomis took the place of Ayew up front.
The Swans did find the net soon after through Sigurdsson, but Gomis was adjudged to have impeded Hart in the build-up.
And the visitors did get what they deserved in the 90th minute as Fede Fernandez's sublime through ball sent Gomis in on goal, and his fierce strike flew past Hart and into the top corner.
But, cruelly, in added-on time, the home side stole the points with Toure seeing his curling effort take a deflection before dropping into the far corner.