"It was a great follow up by [Johnson] as he's playing well and had another great game," Joseph said. "It was fun to get the first one out of the way and contribute offensively as well."
Johnson scored his second of the season at 6:07 of the second period, beating Mrazek high on the glove side to make it 2-1.
Necas tied it 2-2 with his first NHL goal, a one-timer off a pass from Warren Foegele at 12:48.
"It was a little bit in front of me so I was in kind of a weird position," said Necas, who played his eighth NHL game. "But I hit the puck good and it ended up in the net."
Gourde gave the Lightning a 3-2 lead at 7:02 of the third period with a power-play goal. Ondrej Palat recovered a loose puck down low and passed to Gourde at the hash marks, where he beat Mrazek on the stick side.
"[Palat] made a very good pass to me and I tried to get it off as quick as I could but it hopped over my stick," Gourde said. "When I finally got the puck back, I shot it right away. I think it squeezed through his arm."
Johnson completed the hat trick with an empty-net goal at 18:04 to make it 4-2.