Title contenders last season, Ilves have endured a tough beginning to this campaign with one win in eight matches, and nothing summed up their start better than when Julius Tauriainen's cross to the near post was turned into his own net by goalkeeper Otso Virtanen just two minutes in.
But the Tampere side were level again after 18 minutes when Goudouss Bamba got in behind the defence to take down Matias Rale's ball forward and stab the ball home. Yet, that was as good as it got for the hosts, who conceded again 10 minutes later when a low cross was batted down by Virtanen into the path of Tauriainen, who applied the simple finish.
The visitors extended their lead shortly before the hour mark after Bismark Ampofo was brought down inside the box by Bamba, and Jasse Tuominen placed the resulting penalty into the top corner in style.
It's three wins on the bounce now for FC Inter since their only loss so far, while Ilves' drop to 10th after their three-game unbeaten streak came to an end.
A run of four games without a league win is over for KuPS after they cruised to a home win over Jaro, who remain bottom of the table on goal difference after three straight losses.
The deadlock was broken in Kuopio after 34 minutes, when a long ball forward from Gustav Engvall was taken down brilliantly by Bob Armah, who cut inside the last defender before guiding it home with a cool finish.
Armah wasn't done there - he scored an equally impressive second five minutes into the second half, as this time he chested down Saku Heiskanen's crossfield pass and curled another low strike beyond the goalkeeper.
Four minutes from time, KuPS put the icing on the cake when Joslyn Luyeye-Lutumba teed up Valentin Gasc for his first goal since October. The win takes the champions a point clear of AC Oulu, having played a game more.