Police and football fans clashed after the south Wales city derby, but no major problems were reported.
The Swansea-Cardiff match ended in a 2-2 draw and police praised the "vast majority" of the sell-out 18,053 crowd.
South Wales Police said there had been six arrests after the game at the Liberty Stadium for isolated incidents.
Bottles and stones were thrown from a crowd outside the ground but people eventually dispersed. Two police officers suffered minor injuries.
After the match, there was a minor stand-off between 40 of 50 fans and a group of police.
Two police officers were injured after what were described as "minor isolated incidents".
The policing operation was a success and this is down to the police, the clubs and the genuine supporters working together
Chief Supt Mark Mathias
But it was far better than incidents after the two clubs played each other in a Carling Cup match in September, which led to more than 30 arrests.
Match commander Chief Supt Mark Mathias said: "The manner in which a vast majority of both the Swansea and Cardiff fans conducted themselves was exemplary.
"There was a different atmosphere altogether from the last game. However, there was still a small element that were intent on causing trouble.
"There was one area of disorder after the game which resulted in my officers coming under attack from around 50 individuals. Two officers were injured but not seriously."
Mr Mathias added: "There were a total of six arrests, and as a result of the incident more arrests will follow. I must emphasise though that the policing operation was a success and this is down to the police, the clubs and the genuine supporters working together and I would like to thank all those concerned."
There were no problems reported ahead of the match, which kicked off early at 1115 GMT to try to avoid trouble.
Those involved in problems at the earlier match were kept away from the stadium either by court banning orders or as part of their bail conditions.
Cardiff fans were allocated around 1,650 tickets and were transported on coaches from Ninian Park, which were then escorted into Swansea by police.
Officers had said they would have a "significant" presence throughout the day to ensure that "genuine" fans enjoyed the game.
The match ended in a dramatic draw, with both sides also having a man sent off
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