Following consecutive league draws, KuPS faced pressure to secure three points at home against struggling Haka despite a long and unproductive trip to Kazakhstan midweek, where they were eliminated from the UEFA Champions League by Kairat Almaty.
However, the pressure did not affect them, and they took the lead after just 11 minutes when Bob Armah delivered a low cross for Agon Sadiku to finish off.
Sadiku had to leave the field after only 27 minutes, but KuPS needn't have been concerned, as it took his substitute, Mohamed Toure, just four minutes to score and make it 2-0.
Haka made their own adjustments at halftime, which proved effective as they pulled back into the game six minutes into the second half through Danila Bulgakov. However, hopes of a comeback were dashed just before the hour mark, as Toure scored his second of the match.
The 3-1 victory for KuPS has lifted them to third place, one point behind Ilves and three points behind Inter Turku. The top two teams are both set to play on Monday, with Inter facing HJK, who have dropped to fourth place. Haka remains winless in five matches and sits in 10th place.
Haka has at least managed to avoid slipping further down the standings, after 10-man AC Oulu lost 1-0 at home to Jaro.
Onni Tiihonen received a booking with 10 minutes left in the half, and shortly after, the visitors took the lead when Sergei Eremenko assisted Albin Bjorkskog.
Two minutes after the break, Tiihonen's day and Oulu's chances of a comeback worsened as he picked up a second yellow card. The 10 men could not find a way through and faced defeat for only the second time in seven matches across all competitions.
They remain in 11th place, while Jaro's first win in five matches lifts them to eighth.
On Friday night, two teams struggling to secure a win unsurprisingly played to a draw, as VPS tied 1-1 at home against Mariehamn.
Martti Haukioja opened the scoring for the home side in the 63rd minute, but the Vaasa team was denied their first win in eight matches in the 95th minute when goalkeeper Rasmus Leislahti scored an own goal.
The late equalizer marked a fourth draw in their last five matches for the Aland islanders, but they remain winless in six. They drop to ninth place, yet stay just three points behind sixth-placed VPS in the race for Championship Round spots.