Inter are tied for the first place with Atalanta, as both sides are on 40 points. They are now slated to square off against Lazio next week.
Cagliari are in the 18th spot, which is the relegation zone, since they have garnered only 14 points in the Italian top-tier thus far.
Also Read: Four-time Grand Slam champion Naomi Osaka drops hint of retiring from tennis
Inter have now won five straight away matches without conceding a goal, their third time in a single Serie A season in club history and the first time since the 1966-67 season.
The first half was balanced, with Inter controlling possession but creating few clear chances, while Cagliari defended well.
Inter created the first big chance just minutes after kickoff when Marcus Thuram unleashed a volley that Cagliari keeper Simone Scuffet managed to deflect to safety.
Martinez came close around the half-hour mark when a cross from Calhanoglu sailed past everyone but the diving header went narrowly wide from almost on the line.
Bastoni broke the deadlock for Inter after 53 minutes when he headed in a cross from almost the byline, sending the ball in a near-perfect loop that dipped just under the bar.
(With Reuters inputs)
