Juventus and Napoli will both be nursing throbbing Champions League hangovers when they resume their Serie A campaigns at the weekend, although Rafael Benitez's side might find it easier to pick themselves up.
Third-placed Napoli clearly gained heart from beating Arsenal 2-0 on Wednesday and winning their fourth match out of six in Group F which also featured last season's runners-up Borussia Dortmund and former champions Olympique Marseille.
Napoli's Benitez is still rebuilding his side following the signings of Raul Albiol, Jose Callejon and Gonzalo Higuain and the departure of Edinson Cavani.
Mazzarri transformed Napoli in his four years in charge, leading them into the Champions League for the first time.
"I think we should look at this as a stage during our growth process and regard it as proof we are on the right track," said Benitez after the win over Arsenal.
"The supporters should be proud of what Napoli have achieved."
"We did very well in Europe because there are more spaces than in Serie A," he added. "Our Champions League campaign has been very good and to be so high up the Serie A standings with a new team is an achievement.
"I think the process means bringing in young players who can be here for many years and be part of the long-term project.
"Against Arsenal, we proved that with two or three additions we can compete in Serie A and at another level in the Champions League. In Serie A, with Juventus and Roma doing so well, our results don't seem as impressive, but the truth is we've done very well."
Match facts (courtesy of Opta)
Internazionale have beaten Napoli 62 times in Serie A, more than against any other side.
On the other side, Napoli have enjoyed 41 wins against Inter in the top-flight – only against Fiorentina have they won more often, 42.
Napoli have won three of their last four league meetings with Inter in Serie A, losing the other.
Napoli are unbeaten in their last seven Serie A encounters with Inter at the San Paolo (W5 D2).
Napoli drew 3-3 against Udinese last Saturday, after nine consecutive Serie A fixtures without one of their games ending level (W6 L3).
Rafa Benitez’s side have conceded goals in each of their last six league fixtures.
Napoli are without a win in their last two home games in Serie A – the last time they failed to win for three consecutive league fixtures at the San Paolo was back in March 2010.
Inter are unbeaten in their last eight Serie A games (since their 0-3 defeat at home vs Roma), but have drawn each of the last three.
Inter are still unbeaten away from home in the current Serie A campaign (W3 D4).
Napoli have scored the most goals in the first half of play (19), while Inter have netted the most goals after half-time (20).
Rafa Benitez was Inter manager in 2010 (15 league games, 40% wins percentage), while Walter Mazzarri was in charge at Napoli from 2009 to last summer (145 games, 50.3% wins).
Gonzalo Higuaín has provided four assists in Serie A so far, as many as Edinson Cavani managed last season in the whole campaign.
European matches covered live on our site over the weekend (all kick-off times GMT):
Eurosport / Opta / Reuters