Met fans were bloodthirsty for Mike Hampton last night. And Hampton played right into their bloodlust by getting bled dry in the first inning.

They say misery loves company, and the Shea crowd of 28,510 was thrilled to see Hampton return to the city he spurned in the offseason because of a $121 million offer from the Rockies .

With signs of “traitor,” boos every time the former Met lefty came to bat and gleeful cheers when Mike Piazza smashed a tape-measure homer in the second inning, the Met faithful watched Hampton’s season continue to flame out with Colorado’s 5-2 loss.

“It was great, to be honest with you,” Hampton said of the crowd. “The fans were in the game. What more can you ask for?”

Hampton allowed three unearned runs in a 41-pitch first, getting victimized by a rare error when leadoff hitter Matt Lawton was caught between first and second on a steal attempt. Second baseman Brent Butler made an errant throw back to first after Lawton stumbled and reconsidered a swipe of second.

The Mets would subsequently take a 4-0 lead on an opposite-field RBI single by Piazza, a wild pitch that plated Edgardo Alfonzo and a two-run single by Rey Ordonez.

“Hamptie probably could’ve gotten out of the inning with a lot less,” Colorado manager Buddy Bell said.

The Mets never had a shot at re-signing the 28-year-old lefty. Hampton (12-10) was already distancing himself from the club before the Subway Series ended.

“Everyone had a gut feeling, because everybody who talked to him about anything about what was happening off the field, he didn’t like it so much,” manager Bobby Valentine said before the game. “He enjoyed the on-the-field stuff and the clubhouse stuff.”