Metsa pushed the Buffalo lead to 5-0 at 1:54 of the second period after he intercepted a clearing attempt by Lightning forward Anthony Cirelli and scored on a wrist shot from above the hashmarks that beat Vasilevskiy on the stick side.
"I'm never really chasing it, I just try not to and I feel like I get in trouble when I do," Metsa said. "I'm just trying to play the right way and good things have always happened for me. Tonight was one of those nights."
James put the Lightning on the board 5-1 at 16:03. Mattias Samuelsson's clearing attempt off the left boards was intercepted by Hedman, who passed to Oliver Bjorkstrand in the slot. Bjorkstrand fed James, who beat his man out of the corner to get the wrist shot off.
"We're a proud group and we know what works for us," Hedman said. "We've just got to get back to that, have a good practice on Monday and get back to our habits and get everyone together to make sure we're ready to go on Tuesday (at the Minnesota Wild)."
Alex Tuch made it 6-1 at 3:43 of the third period with a power-play goal. Tuch's wrist shot from the point was helped by center Ryan McLeod providing the screen in front of Johansson.
Hedman made it 6-2 at 5:27 with his first goal of the season, a slap shot from above the left circle.
James exited the game with 2:48 left following a hit from Michael Kesselring against the boards. Kesselring was issued a cross-checking minor penalty for the hit, and Cooper had no additional updates on James following the game.
"I thought we got off to a great start, skated really well, moved the puck well, supported the puck well coming out of the zone that led to a lot of good opportunities," Buffalo coach Lindy Ruff said. "I thought tonight we made some good plays and then we put them in the back of the net."
NOTES: Thompson has eight points (four goals, four assists) during a seven-game point streak. ... Lightning forward Nikita Kucherov had his 12-game point streak (eight goals, 20 assists) snapped. ... Sabres forward Zach Benson had a secondary assist in his return to the lineup after missing the previous four games. ... Cooper had no additional update on Gage Goncalves, who left the game early in the second period.