MK Dons' on-loan striker Alan Smith was attacked by Huddersfield Town fans after the teams' League One play-off match on Tuesday night.
Smith scored the Dons' winner in stoppage-time as they bowed out 3-2 on aggregate, much to the joy of invading Town fans.
Ex-Leeds and Manchester United striker Smith was roundly booed by the Yorkshire hordes when he was introduced in the 81st minute.
And as home supporters poured onto the turf to celebrate their club reaching Wembley, some fans confronted the 31-year-old.
The first punch was thrown by a Town fan, and Smith immediately reacted as further blows were exchanged before MK Dons manager Karl Robinson, along with a police officer and a couple of stewards, intervened.
Eventually, Smith was shepherded away.
Robinson told the Yorkshire Post: “I ran on the pitch to get him off, which I know my wife will kill me for. I grabbed Alan and got him in the tunnel.
“Alan was spat at, punched and kicked, the lot. Alan defended himself. He said it was typical of the reaction he gets at places like this.
“One or two idiots spoiled what was a wonderful spectacle. Huddersfield Town deserve tremendous credit and so do their fans but one or two mean the talking point is not just the game."
Huddersfield will play Sheffield United in the play-off final.