The Blues' Women's Champions League clash against Juventus was momentarily stopped as the pitch invader entered the field appearing to want a selfie with Chelsea's Magdalena Eriksson.
The fan was heckled by supporters sat in the stands as he remained on the Kingsmeadow pitch, but those groans turned to cheers when Kerr barged him over.
You can see how the incident unfolded in the video above. Warning: the video contains strong language.
Kerr, who scored a stunning chip in Chelsea's FA Cup final win over Arsenal, was then cautioned by the referee.
The incident sparked a conversation about player safety in the women's game with Chelsea boss Emma Hayes raising awareness for it in her post-match comments.
Hayes said: "He could have waited until the end to have a photograph if he really wanted one. But jokes aside, we do have to think about player safety.
"We've seen with the growth of the game there is this sense of the players being more in demand.
"It should serve as a reminder to us all in our stadiums and with our stewards that we've got to put player protection first."
The match, which finished goalless, denied Chelsea the chance to reach the quarter-finals with a group match to spare.
They need to just avoid defeat in their final match at Wolfsburg on December 16 to guarantee their spot in the last eight.