Rosenborg secured their first Tippeligaen for three years with a 2-0 win away to closest rivals Molde on Sunday.
Second-half goals from Steffen Iversen (78) and Trond Olsen (85) secured the victory which moved the Trondheim club 17 points clear just four games remaining.
Last season's champions Stabaek took a tighter grip on third place with a 3-1 win at home to Stromsgodset. Stabaek went ahead through Daniel Nannskog (39) but the match seemed to be slipping away when Jon Inge Hoiland was sent off after 72 minutes and Mohammed Keita equalised three minutes later.
The hosts were back ahead a minute later, however, when Daigo Kobayashi converted a penalty and Nannskog bagged his second seven minutes from the end. Bodo/Glimt remained in the drop zone after second-half goals from Bojan Zajic (51) and Harmet Singh (80) consigned them to a 2-0 defeat against Valerenga.
Lyn Oslo moved to the brink of relegation after a 1-0 defeat at home to Tromso left them ten points adrift of safety. Ivar Strand scored Tromso's winner after 55 minutes.
Sandefjord's Martin Jensen scored the only goal of the game after 51 minutes as his side beat IK Start 1-0 while Viking FK and Aalesund played out a 1-1 draw. Aalesund's Khari Stephenson scored a 78th-minute equaliser to cancel out Borre Steensild's 19th-minute opener.