A prolific scorer with 322 regular season goals to his name, Stamkos missed almost 11 months recovering from a torn lateral meniscus in his right knee.
Stamkos made it 3-1 with a power-play goal at 3:49 of the second period from the low left circle.
The goal was also one for the record books, as it allowed Stamkos to move into a tie with Vincent Lacavalier for the franchise record (112) for power play goals. Rust scored on the power play to cut the deficit to 4-3 with 5:36 to go in the period.
Koekkoek's first National Hockey League goal gave the Lightning a 1-0 lead at 6:07 of the first period. 5, Pittsburgh, Sheary 3 (Ruhwedel, Niemi), 8:58.
Third Period_9, Pittsburgh, Hunwick 1 (McKegg, Kessel), 10:01.
Stamkos' goal, his first since November 15, came on a power play and gave the Lightning a 3-1 lead at 3:49 of the second period.
Kris Letang assisted on Guentzel's goal and joined Paul Coffey (332) as the only Pittsburgh defenseman to reach 300 assists.
You have to feel good for D Slater Koekkoek, whose patience was rewarded with a career night Thursday against the Penguins.