Both sets of fans made sure they could get as close to each other - as close as lines of police would allow them, that is.
As kick off approached, derby fever was in full swing with a sell-out crowd in place.
The Liberty Stadium was literally bouncing, like it never has done before.
Every ball and kick was cheered and an even louder one came when Cardiff-born Joe Ledley was booked for a foul on Leon Britton.
But the first half failed to see any goals and honours were even at the break, with both sets of supporters content that they were not behind.
That all changed 11 minutes into the second half when Swansea's Spanish midfielder Jordi Gomez stepped up to drive a free-kick low into the bottom left-hand corner.
Cue the eruption of cheers from the majority of the 17,411 crowd.
There was a heavy police presence and trouble after the game
Then chants of "there's only one team in Wales" and "let's all have a disco" rang around from the home crowd.
They were to celebrate further with 15 minutes to go when Stephen McPhail was sent off for Cardiff after picking up his second booking.
The response from the Bluebirds fans was "1-0 to the referee."
And as the match drew to an end, deafening whistles echoed around the stadium as Swansea fans awaited full time.
It came, and cue more celebrations.
The only sour note was minor skirmishes inside the ground when rival fans tried to get at each other as Swansea fans taunted their rivals.
Outside the ground, the less said the better.
That aside, it was a great advert for Welsh football. Roll on 30 November.
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