Both sides have secured places in the Championship Round, but with points carrying over, Ilves' three points are as important as any other they will pick up this season.
The goal that secured them arrived with just over a quarter of an hour played - a long clearance from goalkeeper Faris Krkalic wasn't dealt with by defender Luka Kuittinen, allowing Roope Riski to run in unopposed and slot coolly past Eetu Huuhtanen.
In response, Inter Turku had more of the ball and more shots both on and off target, but they could not grab an elusive equaliser.
The closest they came in the second half was when Jean Botue's header beat Krkalic and the striker began to wheel away in celebration, only for Sauli Vaisanen to get back and hook the ball off the line superbly.
1-0 to the Lynx was how it finished, giving them a second win in a row and moving them to 42 points - one shy of FC Inter.
On Friday night, VPS gave themselves a huge boost in the race for the final Championship Round berth by coming from behind to beat KTP 3-2 for their first win in 11 matches.
It looked as if the home side's dreadful run would continue when Rangel scored to put the bottom-placed side in front on 12 minutes with an acrobatic effort into the top corner, before the same player doubled the lead from the penalty spot 10 minutes later.
But Maissa Fall changed the complexion of the game by getting the men from Vaasa back into it with a goal on the stroke of half-time, and VPS came out for the second half with all the momentum, capitalising within three minutes of the restart as Fall completed his brace.
The comeback was completed before the hour mark - Nicolas Fleuriau's effort was spilt by goalkeeper Madou Diakite, and following in well was Yassine El Ouatki to stab home.
VPS' first win since 14th June takes them up to sixth for the time being, ahead of Gnistan on goal difference, with Jaro three points further back. Both sides will be in action later this weekend.