Matteo Darmian was the unlikely hero as Inter made it 11 league wins on the spin with a 1-0 triumph over Cagliari, in the process restoring their 11-point lead at the top of Serie A.
Antonio Conte's table-topping side turned in a sluggish performance in the early kick-off on Sunday (AEST), though they eventually scored the only goal of the game with 13 minutes remaining.
Darmian arrived at the back post to convert Achraf Hakimi's low cross from Inter's right flank, the former Manchester United defender's finish finally breaking Cagliari's stubborn resistance.
Milan had closed the gap to the leaders on Sunday thanks to a 3-1 triumph at Parma, despite a red card for Zlatan Ibrahimovic after 60 minutes.
Inter appeared in danger of failing to win in the league for the first time since January 23 against opponents who arrived at the San Siro having lost three on the spin, a run of results that had increased the prospects of Cagliari dropping into the second tier.
However, Leonardo Semplici's strugglers frustrated their hosts for the majority of proceedings, aided by an excellent performance from Guglielmo Vicario.
The visitors' goalkeeper twice kept out long-range attempts from Christian Eriksen, as well as denying Darmian in the first half.
Stefano Sensi also saw a strike kept out by Vicario, who had some help from the crossbar when Stefan de Vrij's powerful header from Eriksen's delivery left him rooted to the spot.
Conte sent on Lautaro Martinez in the 70th minute, though it was fellow substitute Hakimi who made the more telling contribution in a cameo appearance, delivering the ball into the path of Darmian to slide in and finish.
Cagliari tried to find a response and Joao Pedro went close with a header from a Gabriele Zappa cross in a frenetic finish – but Inter held firm, moving them a step closer to a first league title in 11 years.