The last of them saw midfielder Tom Williams depart under the double booking rule.
His foul on Bas Savage – Bristol's giant forward - in the final 10 minutes was typical of the nature of this tempestuous encounter.
Earlier this season Swansea thrashed Bristol 7-1 and manger Brian Tinnion lost his job. Now after a busy time in the market place, Swansea were favourites to record a double.
But a flurry of cards cost them the game and will now cost them an FA fine.
There have been few more busy minutes for referee Clive Fenton than the few he added on to the end of the first half.
He found himself holding up four cards and Swansea, who collected three of them, slipped behind to a piece of abject defending.
The last card of the period came when Andy Robinson slid in behind David Cotterill about 15 yards into the Welsh side's half.
Then as Alex Russell's free-kick bounced into the area, keeper Willy Gueret had two chances to grab it but each time lost out to Louis Carey who finally forced it into the net.
The flare-up began with Bristol's Bradley Orr putting in a crashing tackle on Williams.
With so much baggage from the past, tension was always close to the surface.
Swansea had spiced up their promotion hopes with several big signings but manager Kenny Jackett made five changes in an attempt to end a run of four draws in five games.
His new attacking pair of 17-goal Lee Trundle and Rory Fallon were clearly going to take time to blend and before the goal the best chance had also fallen to the home side.
Teenager Cotterill rounded Gueret in some style but his shot lacked conviction and was cleared off the line.