Bassirou Diomaye Faye’s extraordinary rise caps a rollercoaster period in Senegalese politics that caught many off-guard.
Months in jail alongside ally and kingmaker Ousmane Sonko ended suddenly, with the pair released the week before the presidential election.
Now Mr Clean, as he’s nicknamed, must get to work on the sweeping reforms he has promised.
“Methodical” and “modest” are words often used to describe the tax collector, who celebrates his 44th birthday on Monday.
Mr Faye fondly recalls his rural upbringing in Ndiaganiao, where he says he returns every Sunday to work the land.
His love and respect for village life is matched by his deep distrust of Senegal’s elites and establishment politics.
“He’s never been a minister and wasn’t a statesman so critics question his lack of experience,” analyst Alioune Tine tells the BBC.
“But, from Faye’s point of view, the insiders who’ve run the country since 1960 have made some catastrophic failures.”
Fighting poverty, injustice and corruption are top of Mr Faye’s agenda. While working at the Treasury, he and Mr Sonko created a union task force to tackle graft.