The 50-year-old geologist, who was brought up in a poor family, served as Mr Wade's prime minister between 2004 and 2007 and before that held the interior and mines portfolios.
He also oversaw the successful re-election of Mr Wade five years ago, heading his electoral campaign - and went on to become president of the National Assembly.
And he has twice served as mayor of his home town of Fatick, 120km (75 miles) south of the capital.
But the politician proved he was no ruling party lackey when he dared to call the son of the outgoing president before MPs over allegations of mismanagement. Sall fell out of favour with Wade's government, quit the party and struck out on his own Photo:Reuters
Sall fell out of favour with Wade's government, quit the party and struck out on his own Photo:Reuters
Critics say Mr Wade, 85, had been grooming his son, Karim, to succeed him, pointing out that he was already running the powerful cabinet portfolios of transport and energy.
Despite this, Mr Sall had summoned him for questioning about the alleged lack of transparency over the funding for the 2008 summit of the Organisation of the Islamic Conference (OIC).
In the end, he resigned from his post in the National Assembly and from the ruling PDS party and set up his own movement, APR-Yakaar.
Since then Mr Sall was at pains on his campaign trail to say that country should come before party and ethnicity.
Although he was born in Fatick, his parents are Fula people from the north of Senegal and he says growing up as an outsider has given him his vision.