The Finns (2-0) have beaten a pair of overmatched teams by a combined score of 14-5.
Finland, which also beat Austria 8-4, will be tested in the preliminary-round finale against the defending Olympic champion Canadians (2-0) on Sunday for a guaranteed spot in the quarterfinals.
Norway (0-2) will have a shot Sunday against Austria (0-2) before likely being relegated to the playoff round to compete for a spot among the final eight in the 12-nation tournament.
Selanne silenced any questions about whether he'd play after leaving the previous game with an upper-body injury by starting the game scoring early.
The 43-year-old forward, the oldest hockey player in the Sochi Games, scored on a wrist shot 5:46 into the game.
Lauri Korpikoski scored his first of two goals about a minute later. Korpikoski and Olli Jokinen had goals midway through the second period that made it 5-0.
Norway went on a 5-on-3 power play for 1:30 early in the third period and took advantage, avoiding a shutout as Per-Age Skroder scored.
Kari Lehtonen finished with 20 saves for the Finns.
Norwegian goaltender Lars Haugen was pulled after giving up three goals on 13 shots in the first period. Lars Volden didn't do much better in net, allowing two goals on 15 shots in the second period.
Finland wasn't finished scoring, even though the only question was what the final score would be as Olli Maatta scored late in the game for a five-goal victory.
While the Finns haven't gotten as much attention as Russia, Canada, Sweden and the U.S. in the tournament, they have proven to be a force in best-on-best hockey at the Olympics.
Finland is the only nation with three medals since NHL players joined the Olympics in 1998.