A few minutes into the match, the ferret-like furry critter made a mad dash onto the pitch as the crowd cheered and the players were brought to a standstill with bemusement.
The 20 seconds of marten mania came to a temporary halt as the animal ran up into the stands, but the referee had to blow his whistle to stop the game again when it re-emerged.
Zurich defender Loris Benito made a dive that Gianluigi Buffon would be proud of to catch the creature, but he was bitten on the finger while trying to carry the animal away, allowing the chaos the resume in Switzerland.
However, gloved Zurich goalkeeper David da Costa stepped up to restore sanity in the tie by finally ejecting the marten from the pitch, and he and his team-mates were eventually rewarded with a 4-0 win on Sunday.
Extra Time remembers last season when a cat caused play to halt at Anfield before a chicken (fittingly) was introduced in one of Blackburn’s matches before their Premier League relegation, but this marten certainly takes away the award for the cheekiest pitch invader in recent memory!