Napoli suffered a cruel exit from the Champions League after beating Premier League leaders Arsenal 2-0 on Wednesday.
The Italian side were heading for the last 16 until Borussia Dortmund scored a winning goal in the 87th minute at Olympique Marseille. The German side's 2-1 victory meant all three teams finished on 12 points in Group F, but Napoli were eliminated because of their head-to-head record.
"It's difficult to explain how deeply we are disappointed," said Napoli defender Christian Maggio. "Our group was incredible and we matched two fantastic teams - we are out, but with our heads high and no regrets."
Gonzalo Higuain scored Napoli's first in the 73rd minute as the hosts came to life after a dismal opening hour which Arsenal controlled, without looking like scoring. Jose Callejon scored the home side's second in injury time but it was not enough.
It was the 14th season in a row that Arsenal, who had captain Mikel Arteta sent off for a second bookable offence in the 75th minute, have reached the last 16.
They finished runners-up to Dortmund, last season's losing finalists, in the group.
"It was a very difficult game, Napoli played very well tonight," said Arsenal manager Arsene Wenger. "I feel for Napoli. It was a difficult group and one team had to be knocked out ... they can feel very hard done by to be that team."
Wenger said Napoli may have "played a bit with the handbrake on", easing the pressure on the English side, when they thought a 1-0 win would take them through.
Benitez agreed Napoli were influenced by what was going on in Marseille.
"We should have scored a goal earlier, but we knew it was 1-1 in Marseille and we were afraid to push too hard in case Arsenal hit us on the break," he told Sky Sport Italia.
"The team gave its all and deserved both to win and to qualify, but that's football."
The win will at least lift some of the pressure off Benitez whose team have suffered a loss of form in the league and were jeered off on Saturday after a 3-3 home draw.
BEST OPENING
Olivier Giroud had Arsenal's best opening of the first half at a half-empty San Paolo when his left-foot shot was parried by Rafael Cabral.
Napoli barely threatened although Wojciech Szczesny gave them a helping hand when he chipped an attempted clearance straight at Gonzalo Higuain's head, but the ball ricocheted off target.
Napoli came to life after Lorenzo Insigne replaced the ineffective Goran Pandev early in the second half.
Pablo Armero wasted an excellent chance when he shot straight at Szczesny, then Higuain fired over from a good position on the right.
The breakthrough came when Higuain played a one-two with Callejon, received the ball with his back to goal and scored on the turn with fine, low shot into the far corner.
Arteta was given a second yellow card for a lunge from behind on Callejon and, with Dortmund drawing in Marseille, Napoli seemed content with the narrow win.
But the German side's late goal forced Napoli, who now needed to win by three clear goals, into frenzied attack and Callejon lofted the ball over Szczesny after a great pass by Insigne. But it was a case of too little, too late.