Bodo/Glimt has won the championship the previous two seasons, while Viking has not won the title since 1991.
In total, Viking, which was founded in 1899, has now won the Norwegian championship nine times.
Viking has got Peter Christiansen and Anders Baertelsen in the squad, both played a part in Sunday's victory. Peter Christiansen played the entire match, while Anders Bærtelsen came on for the last 15 minutes of the game.
At Vålerenga, the Danes Oscar Hedvall, Elias Sørensen, Carl Lange, and Kevin Tshiembe were in the match. But none of the field's six Danes got on the scoreboard.
In the first half, Norwegians Edvin Austbo, Martin Ove Roseth, and captain Zlatko Tripic got on the scoreboard for the home team.
Valerenga created a bit of tension five minutes into the second half when Elias Hagen reduced the deficit to 1-3.
But the away team did not get any points closer.
Kristoffer Haugen and Kristoffer Askildsen scored for Viking, who thus had five different Norwegian goalscorers on the scoreboard.
Bodo/Glimt won their last match 5-0 at home over Fredrikstad. In that match, substitute Mathias Jorgensen scored the last goal.