Londoner Napa suffered his sixth defeat as a professionalIan Napa failed in his bid to claim the European bantamweight title as he suffered a unanimous points defeat to champion Simone Maludrottu in Dagenham.
The 28-year-old Hackney stylist responded well after a disappointing start and briefly threatened to cause an upset against his Italian opponent.
But despite a high punch count Napa's lack of power again proved decisive.
And Maludrottu, the WBC's number one contender, weathered the storm to win on all three judges' cards.
Napa, the former ABA Champion, swarmed forward for the entire 12 rounds but the better quality punching came from the Italian.
And Maludrottu, making the seventh defence of his title, sealed the victory with scores of 117-112 117-112 116-113.
Napa said: "It was a good fight and all credit to the guy. I was at him for the whole 12 rounds but he's a good fighter."
A lack of height will always prove a handicap for Napa, but he ruled out trying to drop down a division.
"I'm not going to kill myself to be a super-fly," he said.
Maludrottu, also 28, claimed: "I am the best bantamweight in the world and I will be world champion. It is just a matter of time."