Goals from Ismaila Sarr, Habib Diarra and Cheikh Sabaly inflicted England’s first ever defeat against African opposition at Nottingham Forest’s City Ground after Harry Kane had given the hosts an early lead.
Tuchel was scathing in his criticism of his side’s dreary display in beating minnows Andorra just 1-0 in World Cup qualifying on Saturday.
The German, who was appointed with the task of ending England’s wait since 1966 for a major tournament win, has now suffered his first defeat in four games in charge.
“Not good enough. We had moments, but with and without the ball things aren’t clicking, we’re not finding the right tempo,” said England captain Kane. “We’ve lost that aggressive nature that we had.”
Tuchel responded by making 10 changes, with Kane the only player to retain his place.
It took just seven minutes for the Bayern Munich striker to maintain his record of scoring in every game since Tuchel took charge.
Former Chelsea goalkeeper Edouard Mendy should have done better when he could only parry Anthony Gordon’s shot into the path of Kane, who tapped in his 73rd international goal.
Dean Henderson was given a rare chance to impress in the England goal as Jordan Pickford was relegated to the bench.
The Crystal Palace stopper made impressive saves from his club team-mate Sarr and Idrissa Gana Gueye.
But he was helpless when Sarr made the most of a lack of concentration from Kyle Walker to meet Nicolas Jackson’s cross and fire into the bottom corner.
England had never lost to African opposition in 21 previous matches but Senegal had been beaten just once from open play since losing to the Three Lions at the 2022 World Cup.
Diarra was afforded acres of room to run in behind the England defence and slot between the legs of Henderson to put the visitors in front just after the hour mark.
Mendy made amends for his role in the opening goal with fine saves to deny Bukayo Saka and Morgan Gibbs-White a swift equaliser.
England thought they had levelled late on when Jude Bellingham smashed home from a corner.
But the goal was ruled out for a handball by Levi Colwill before the ball broke to the Real Madrid midfielder.
Senegal made the most of that reprieve to seal a famous win in stoppage time when Sabaly rounded off a slick counter-attack.
Boos rained down from the disgruntled home support to leave Tuchel with plenty to ponder before England are next in action in September. (AFP)