Substitute Gustav Isaksen's goal gave Lazio a 1-0 win away to Atalanta on Sunday, boosting the visitors' hopes of a top-four finish in Serie A and leaving the hosts nervously looking over their shoulders.

Lazio move up to sixth on 55 points, one point behind fifth-placed Juventus, who drew with AS Roma later on Sunday. Atalanta remain third on 58 points, two clear of fourth-placed Bologna, who host Napoli on Monday.

Atalanta led the table for a spell in December during a run of 11 consecutive league wins, but the wheels have come off since then and Gian Piero Gasperini's side have won just four of their last 14 matches.

The first half was played at a sluggish pace, with neither side managing a shot on target, and there was little to brighten a dull afternoon at the Gewiss Stadium.

Lazio finally forced Marco Carnesecchi into a save early in the second half, the Atalanta goalkeeper tipping over Fisayo Dele-Bashiru's long-range effort, and minutes later he made another impressive stop to deny the home side.

Sead Kolasinac pulled the ball back for Mateo Retegui on the edge of the six-yard box, but the league's top scorer was denied by Christos Mandas' reflex save.

The goalmouth action continued and Lazio took the lead nine minutes after the break when Dele-Bashiru headed a long ball into the area from his keeper and half-time substitute Isaksen slid in to fire past Carnesecchi.

Mandas made another fine save from Davide Zappacosta's shot from the edge of the area as the hosts desperately searched for an equaliser, while Carnesecchi kept out Luca Pellegrini's deflected cross to prevent Lazio from doubling their lead.

Atalanta had a late chance, but Marco Brescianini sent his header wide as the hosts slipped to a third successive defeat, while Lazio returned to winning ways after three games without a win.

Atalanta have failed to win in their last seven home league games, with their last win coming in December, and their Champions League hopes appear to be running out of steam.