The striker looked rich in confidence after his drought-breaking goal for France last weekend as a pair of delicate touches late in the first half sliced open a Cardiff defence that until then appeared in good order.
Neil Warnock's pre-match promise not to "shut-up shop" took shape when Bamba stunned an expectant Stamford Bridge crowd, prodding in defensive partner Sean Morrison's header.
The Belgium captain received the ball just outside the Cardiff box in the 37th and surged past a defender before driving a powerful finish across goal to equalize.
But the Blues came back with a vengeance and have now won their first five games of the season.
That was however 21 minutes after visiting Cardiff had shot into the lead thanks to Ivorian import Souleymane Bamba.
"Chelsea is his home, of course", Sarri said at a press conference, according to FootballItalia.
Moments later Willian produced his own moment of magic with a wonderful curling effort from 20 yards that bent into the top corner.
Chelsea's Cesar Azpilicueta, left, and Olivier Giroud, right, celebrate with Eden Hazard who scored his side's first goal during their English Premier League soccer match between Chelsea and Cardiff City at Stamford Bridge stadium in London Saturday, Sept. 15, 2018.
The Blues have been playing some great football this season and with top-of-the-table Liverpool travelling to Tottenham this weekend, Chelsea have a great chance to leapfrog the Merseysiders with a fifth consecutive victory tomorrow. I think he can score 30 or 35 goals.