40 seconds after being dropped, Mitchell Marner made it 1–0 to Toronto.
Sweden's Rickard Rakell almost managed to equalize for Pittsburgh in the second period, but the goal was disallowed.
The judge's decision was reviewed and stood.
Less than two minutes later, Toronto's Pontus Holmberg instead stepped forward and made it 2-0 with an ankle shot from the slot.
Another 55 seconds later, teammate William Nylander extended the advantage to 3–0, which was his twelfth goal of the season – and 149th of his NHL career.
Toronto won 4–1 after Rickard Rakell cut back before Nylander added an assist point on the closing goal by Auston Matthews.
The goal record means that Nylander is now the second best Swede in the club's history when it comes to goals.
First on the list is Mats Sundin, who scored a whopping 420 goals.
Börje Salming has the third most goals, with his 148.
However, Salming scored two more goals in his final season in the NHL, playing for the Detroit Red Wings.
Several Swedish goals tonight
Elias Pettersson and Fabian Zetterlund each scored as their teams Vancouver Canucks and New Jersey Devils won their respective games 5–1.