Inter played with the ferocity coach Antonio Conte had been demanding and Sassuolo barely had a sight of goal apart from a curled effort from Filip Đuričić that hit the outside of the right post.
Champions League: Achraf Hakimi to miss Inter Milan's opening game after testing positive for COVID-19
Inter host Bundesliga side 'Gladbach at the San Siro in Group B on Wednesday evening as Antonio Conte's team look to bounce back from a 2-1 derby defeat to AC Milan at the weekend.
Former Watford and Aston Villa player Ashley Young joined Inter from Manchester United in January.
Inter dominated from the start but took until eight minutes from halftime to break the deadlock when Candreva fired home following a pinpoint assist from Sánchez.
Inter Milan needed to win to hold off hard-charging Atalanta in the race for third and took the lead in the fifth minute when Young was left unmarked to volley in Sánchez’s cross.
Romelu Lukaku scored twice to lead Inter Milan to a comfortable 4-0 win over lowly Genoa as they rejoined Juventus at the top of Serie A
Borussia Dortmund and their under-fire coach Lucien Favre hope to maintain the 'feel-good' factor from back-to-back wins as they chase Champions League revenge at home to Inter Milan on Tuesday
Serie A: Alexis Sanchez goes from hero to villain in Inter Milan's victory; Cristiano Ronaldo scores in Juventus win
Sanchez made a big impact in Genoa for Inter Milan, deflecting in Stefano Sensi's long-range opener after 20 minutes and tapping in another Sensi cross two minutes later before getting a red card.
FIFA 2018 World Cup qualifiers: Italy failing to qualify would be catastrophic, says coach Giampiero Ventura
"I'm not thinking about the play-offs, we need to think about the next two matches and then based on who we meet we'll weigh things up," said Ventura.