Gonzalo Higuaín returned to haunt his former club as his early goal proved enough to earn Juventus a 1-0 win at Napoli that leaves the Serie A title race wide open.

The Argentinian striker, who swapped Naples for Turin in July 2016, was passed fit to play despite undergoing surgery on his left hand on Monday. After Pepe Reina saved an early shot from a tight angle, Higuaín latched on to compatriot Paulo Dybala’s through ball in the 12th minute and kept his composure to slot the ball inside the near post.

Juventus, who are chasing their seventh straight scudetto, defended resolutely after Higuaín’s opener and were rarely in danger. Napoli dominated possession but were far from their free-flowing best and slipped to their first league defeat of the season.

The Juventus coach, Massimiliano Allegri, said that everything had gone according to plan. “It was a great test for us. We did very well, leaving them with the possession of the ball in the second half but without letting them create very much.

“Football matches are not just a question of having possession but also of strategy. We sometimes play with an extra defender, depending on the game, but in the end matches are won in defence.”

The hosts’ best chances fell to Lorenzo Insigne but the forward found Gianluigi Buffon in imperious form. Buffon denied Insigne twice and also saved from Marek Hamsik in the first half.

Napoli penned Juventus in their own half after the interval but were repeatedly let down by their final passes. In fact, it was the visitors who came closest to scoring when Reina turned Blaise Matuidi’s volley over the crossbar at point-blank range.

Juventus moved up to second on 37 points, one point behind Napoli. Internazionale are third but will go top with a home win over Chievo on Sunday.

Roma stroll past 10-man SPAL to keep pace at top

Roma also closed the gap at the top in one of Italy’s most competitive title races for years, after a routine home win over struggling SPAL. The giallorossi are fourth on 34 points, with a game in hand on the top two.

Roma players celebrate Kevin Strootman’s goal at the Stadio Olimpico. Photograph: Filippo Monteforte/AFP/Getty Images

The visitors had Felipe sent off in the 11th minute for fouling Edin Dzeko when the Roma forward had a clear run on goal, and Dzeko and Kevin Strootman put Roma 2-0 ahead at half-time.

Lorenzo Pellegrini headed in Aleksandar Kolarov’s cross for the third goal early in the second half, before Federico Viviani pulled one back from the penalty spot.