The striker, who is currently a free agent, was somewhat of a cult figure during his time with the Toffees.
Signed from Lokomotiv Moscow for £13.5million in February 2016, Niasse scored a total of nine goals in 42 games before leaving at the end of the 2019-20 season.
But the former Senegal international showed Everton is still very much close to his heart.
Having left Burton Albion at the end of last season, Niasse currently has weekends to himself.
So the 32-year-old opted to join the family of Idrissa Gueye, his compatriot and former Blues team-mate, in the stands.
There was plenty to cheer about as Neal Maupay's second-half goal delivered Frank Lampard's side their first Premier League win of the campaign.
In addition, Lewis Warrington was at Goodison Park to watch on.
Only the midfielder - who is currently on loan at League One side Fleetwood Town - did not take a vantage point where you might expect.
Rather than the directors' box, Warrington instead was spotted enjoying the action from the Gwladys Street End.
Replying to a fan on Twitter who noticed Warrgiton, he said: "Always. Big win yesterday up the Toffees."
Warrington helped Fleetwood earn a 1-1 draw against Charlton on Saturday.
The Cod Army are a creditable 11th in the third tier, with Warrington playing the entire 90 minutes of their past two matches.