A Birmingham fan who punched Aston Villa's Jack Grealish after invading the pitch was jailed for 14 weeks on Monday as calls mounted for urgent action to prevent potentially life-threatening attacks.
Grealish was attacked by a supporter during the Birmingham derby on Sunday, hours before Manchester United defender Chris Smalling was confronted on the pitch at the Emirates by an Arsenal supporter.
The shocking incidents followed an episode on Friday in which Rangers captain James Tavernier was challenged by a pitch-invading Hibernian fan in his side's stormy Scottish Premiership draw.
Birmingham fan Paul Mitchell, who pleaded guilty to assault and pitch encroachment, blew kisses to supporters at the club's St Andrew's ground as he was led away by stewards following the attack early in the Championship match.
The 27-year-old pub worker, who was handed a 10-year football banning order by Birmingham Magistrates' Court, has also been slapped with a lifetime ban by Birmingham City.
Passing sentence, magistrate Alison Fisher told Mitchell: "This type of behaviour is completely unacceptable — a view shared by your own football club.
"Mr Grealish has stated that he was shocked and scared and feels lucky that it wasn't worse. Players such as Mr Grealish are entitled to protection. We have therefore gone outside of our guidelines in the interests of justice."
In a statement read to magistrates from Grealish, who went on to score the winning goal in Sunday's 1-0 win for Villa, he said: "I cannot help but feel how lucky I was in this incident.
"It could have been so much worse had the supporter had some sort of weapon."
Birmingham issued a statement welcoming the sentence, saying Mitchell's actions had "no place in football".
"The club can confirm that Mr Mitchell is banned from our home ground, the St. Andrew's Trillion Trophy Stadium, for life," the statement said.
"And nor will he have access to purchase tickets for away games involving Birmingham City Football Club, or have tickets purchased on his behalf."
The club said it had banned another supporter for life "for a series of vile and malicious tweets on social media, relating to Jack Grealish and his family", adding that the individual remained the subject of a police investigation.
Writing in his column in the Sun newspaper, former England captain Alan Shearer warned players' lives could be at risk unless there was decisive action.
"It is absolutely disgusting and if we don't stamp it out now, next time it could be a knife," he said.
PFA chief executive Gordon Taylor condemned the attack on boyhood Villa fan Grealish.
"It was disgraceful, cowardly and criminal. We have seen an increase in such behaviour at clubs this season. It's been racist abuse, it's been anti-Semitism and now it's real fear for the safety of players," Taylor told Sky Sports News.
Smalling was confronted by an Arsenal fan following Pierre-Emerick Aubameyang's goal for the Gunners in United's 2-0 Premier League defeat at the Emirates Stadium.
Smalling tweeted: "Commenting would only add to the attention he craved... Disappointed with yesterday's result but we'll learn from it. Looking ahead. Have a good start to the week everyone!"
A man named as Gary Cooper, 30, has been charged with common assault over the incident at the Emirates, police confirmed.
The FA said "a line had been crossed in terms of fan behaviour" and promised to examine security measures at the two matches in question as well as what future steps can be taken.
Rangers manager Steven Gerrard called on fans to take responsibility for their actions after Tavernier became embroiled in a shoving match with a Hibernian fan who jumped out of the stands to kick the ball away.
"Fans have to take responsibility and think before they do these type of things, because if it continues someone is going to get hurt and hurt badly, and no one wants it to get to that stage," said the former England player.