MILAN - Gonzalo Higuain struck his 21st goal in as many games to help Napoli tighten their grip on Serie A with a 4-2 win at Sampdoria as title challengers Inter Milan were stunned by a late Carpi leveller.
Napoli's midfielder Marek Hamsik celebrates after scoring during the Italian Serie A football match Sampdoria vs Napoli on January 24, 2016 at 'Luigi Ferraris Stadium' in Genoa
As Napoli battled to their 14th win of the campaign, Inter paid the price for a series of first-half misses when Kevin Lasagna levelled at the death for the minnows to secure a 1-1 draw at a stunned San Siro.
Napoli now sit five points ahead of Juventus, who host Roma in Sunday's late game, and have a six-point lead on Fiorentina after their 2-0 win over Torino earlier in the day.
Inter have dropped to fourth at six points adrift, enforcing the pundits' belief that it is now a two-horse race for the title.
After what has been a trying week for Napoli, the Azzurri showed their mettle.
Coach Maurizio Sarri was caught in the eye of a homophobic storm after calling fellow coach Roberto Mancini a "poof" during a post-match tirade following defeat to Inter Milan in the quarter-final of the Italian Cup.
Inter drew a line under the controversy on Friday by publicly accepting Napoli and Sarri's apology.
A trip to Sampdoria looked a challenging prospect for Sarri's title challengers, but after ballooning an early chance over Higuain was soon into his usual, predatory stride.
In the ninth minute, the Argentinian pounced on a poor Edgar Barreto back-pass to power towards the area and fire past onrushing Emiliano Viviano.
"Higuain is becoming what I always thought he should be, in other words the best striker in Europe and perhaps the world," Sarri told Mediaset Premium.
"I wouldn’t even exchange him with Robert Lewandowski."
Another Barreto blunder helped Napoli double their lead by the 18th minute, the defender hauling down Raul Albiol and the referee pointing to the spot.
Despite Higuain's chance to match the 22-goal tally that won the league's Capocannoniere (top scorer) award for Luca Toni and Mauro Icardi last season, Lorenzo Insigne stepped up to beat Viviano at his near post.
Napoli were in command but the visitors were pegged back after Carlos Carbonero did well to snatch possession and powered down the right flank.
Sampdoria striker Eder's dummy was crucial, allowing Joaquin Correa to run in and beat Pepe Reina first-time from 12 yards.
A superb piece of individual skill from Napoli captain Marek Hamsik helped Sarri's men restore their lead, the Slovakian shimmying past three players inside the area to toe-poke the ball past Viviano at his far post on the hour.
Sampdoria pulled one back on 73 minutes when Eder rose to meet a corner to fire a glancing header through the legs of Reina, but six minutes later the match was effectively over.
Dries Mertens had replaced Insigne with 15 minutes remaining and only four minutes later the Belgian international took on two Samp defenders before beating Viviano with a low shot at his far post.
Elsewhere, Lazio and Palermo gave their stuttering campaigns a boost by recording impressive 4-1 wins over Chievo and Udinese respectively.
Bologna's purple patch under coach Roberto Donadoni continued with a shock 2-0 win away to Sassuolo, who remain seventh but are now only one point ahead of a resurgent Lazio.