Inter Milan and Lazio shared a goalless draw at San Siro that frustrated both clubs' Serie A ambitions.
Previously unbeaten Inter slipped off the top of the table following back-to-back defeats to Udinese and Sassuolo and on Wednesday the Nerazzurri were knocked out of the Coppa Italia by city rivals AC Milan.
Lazio's bid for a top-three spot had stalled in recent weeks and they enjoyed the best chances to win on Saturday night, most notably when the award of a penalty was overturned following a VAR review.
Avoiding defeat was key for both sides and so the opening stages were spent patiently working out the best way to launch successful raids without attacking recklessly.
Lazio made the first move, with Stefan Milinkovic-Savic picking out Luis Alberto for a cross-cum-shot that forced Samir Handanovic into a low, sprawling save.
Ciro Immobile tested the Slovenian goalkeeper with a rising sighter before, in the 20th minute, the Italy striker found Milinkovic-Savic for a powerful drive that Handanovic palmed away for a corner.
Following that set-piece Lucas Leiva crossed for Bastos, who nodded the ball just over from close range.
Inter created an opportunity on the half-hour mark when Borja Valero crossed for Ivan Perisic, the Croatian winger trying his luck from distance only for Thomas Strakosha to flick the ball over the bar.
Deep into first-half stoppage time Valero attempted to head Luis Alberto's delivery from a corner to safety, instead managing to rattle both the crossbar and Handanovic's nerves.
When play resumed after the interval it was Inter's turn to be proactive and Valero only missed the mark when bursting into the box as Strakosha deflected his attempt onto a post and out.
Lazio were awarded a penalty on the hour mark. Milan Skriniar touched the ball after Immobile had crossed it but there would be no spot-kick as, following a video review, referee Gianluca Rocchi decided the Slovakian defender had not handled deliberately.
After absorbing that disappointment Lazio rallied and in the 74th minute Felipe Anderson activated his turbo to sear through the Inter defence and draw a diving stop from Handanovic.
The Biancocelesti kept coming and when the ball unexpectedly bounced off the referee's back Marco Parolo took advantage by aiming a first-time shot at Handanovic, who showed excellent reflexes.
Felipe Anderson's threat did not diminish as time began to run out at San Siro and the Brazilian was cursing when he blasted over from an excellent position in the middle of the Inter penalty area.
Inter captain Mauro Icardi had endured a quiet evening but almost became the protagonist of the match in the 89th minute. Perisic's effort was missing the target and Icardi almost corrected its flight.