
Paltrinieri led virtually from the start before Finke hauled him in over the final 50m to touch in 7:41.87sec.
The Italian was second in 7:42.11s, with Ukrainian Mykhailo Romanchuk third in 7:42.33s.
“I just wanted to get my hand on the wall. I’m so happy I could switch into another gear,” said Finke.
“It means a lot. Coming into this there was a lot of doubt around American distance so I’m happy to get a medal on board for the team. I’m just really excited.”
Paltrinieri was the top seed, with the fastest lifetime best of the group. He was also the only swimmer in Tokyo to have broken 7:40s in the event.
He went out fast and had a body-length lead after 100m, stretching his advantage as the race progressed.
But he tired in the final 100m, with Finke finding a late burst of speed to overtake him in the dying stages.