After a bruising defeat in Spain on Thursday that brought their UEFA Europa League campaign to a close, Roma were looking to regroup in league action, but a slow start suggested they were still licking their wounds.
Still dominant in possession, Claudio Ranieri’s men first threatened through Artem Dovbyk’s long-range strike that sailed over the bar.
No side in the division had conceded more set-piece goals than Cagliari’s 16 heading into the weekend, and Gianluca Mancini nearly added to that tally when he volleyed a corner inches wide of the target.
The Giallorossi’s laborious performance saw them fail to register a shot on target before the break, with Dovbyk coming closest through a glancing header that drifted past the post.
The visitors sensed an opportunity in the first half’s closing moments, slicing through the Roma defence on the break to find Nadir Zortea in space on the right, but he could only blaze high and wide with a strike that epitomised the lack of attacking quality on show.
Cagliari carried that momentum into the second period, and could have led soon after the restart when Zortea’s cross found Roberto Piccoli, but his shot from close range was well saved by Mile Svilar.
That miss proved costly, as the Islanders’ poor defending saw them concede the opener just after the hour.
Rather than clearing a corner, Nicolas Viola looked to duck under the arriving ball, which instead hit him on the back and presented Dovbyk with a chance on the six-yard line.
The Ukrainian duly converted for his 10th league goal of the season, but Roma were far from clear of danger as Svilar preserved their lead with another impressive save, this time denying Yerry Mina’s header.
The hosts’ efforts to pull away were stifled when Paulo Dybala’s cameo from the bench lasted just 14 minutes before he limped off injured.
Fortunately for them, Cagliari’s lack of attacking threat meant the Giallorossi leapfrogged AC Milan into seventh, leaving them just four points shy of the top four.
The visitors, meanwhile, have now won just once in eight league outings and remain just four points clear of the relegation zone.
Flashscore Man of the Match: Mile Svilar (AS Roma)