Leicester come from behind to deny Everton first win of the season
Jesper Lindstrom spurned a golden chance to put Everton ahead inside the opening four minutes but attacking midfielder Ndiaye spared his blushes eight minutes later to give the visitors the lead and score his first Premier League goal.
Ndiaye, who moved to Merseyside from French club Olympique de Marseille in July, finished off a slick Everton move in the 12th minute to give them the lead, receiving a return pass from Ashley Young and weaving through two defenders to slot the ball past goalkeeper Mads Hermansen.
Dominic Calvert-Lewin, who has two Premier League goals this season, saw his shot on a counter-attack thwarted by Hermansen before Harry Winks's corner led to a scramble in the Everton box and Mavididi fired home in the 73rd minute.
Everton, who squandered a 2-0 lead in two successive Premier League matches before playing Leicester, are in 19th place alongside Wolverhampton Wanderers with one point from five matches and identical records.
Leicester sit in 15th spot with three points from their five matches. Leicester were relegated to the Championship on the final day of the 2022-23 season after they finished two points behind Everton, who ensured their survival in 17th place.
Leicester struggled to manufacture any sense of urgency in their play in the first half but put on a much-improved performance after the interval and kept up the pressure after drawing level.
Everton were missing defenders Jarrad Branthwaite, Seamus Coleman, Nathan Patterson and Vitalii Mykolenko, as well as striker Armando Broja through injury.