Jardim had been at the club for over four years.
Portugal earn comfortable victory in their first match of the U17 qualification phase.
Reports in France have confirmed that this is the end of the line for the young Portuguese manager, who spent over four seasons at the club.
It comes after the Valencia winger was injured in a clash with Barcelona last weekend
Sporting stay fifth in the table, with Portimonense moving out of the relegation zone.
The result sees Benfica leapfrog Braga in the Primeira Liga on goal difference.
It means that all three Portuguese managers in the Premier League won in the same gameweek for the first time this season.
The incredible win sees Sporting go six points clear of their Ukrainian counterparts.
The Portugal squad had a good mix of youth and experience - but also some notable omissions. A run-down of Santos’ decisions.
Fernando Santos announces the side that will be taking on Poland and Scotland in the coming week.
The victory sees Porto go joint top of their Champions League group, leapfrogging Galatasaray in the process.