HJK were comprehensively beaten by leaders Inter Turku in the previous round of fixtures, while Ilves were unbeaten in six Veikkausliiga outings.
That run came under threat with 32 minutes on the clock, though, as Joona Veteli was shown a straight red card for a crunching tackle right under the nose of the referee.
But the 10-men not only held out until after the break, but took the lead 20 minutes into the second half when Oiva Jukkola raced onto a ball over the top from Andre Raymond and finished with style.
That was the signal for HJK to bring on Teemu Pukki, and the veteran needed five minutes to have an impact, teeing himself up and catching the ball perfectly on the volley from the edge of the area.
The Ilves resistence was truly broken two minutes later, when Giorgos Antzoulas completed the turnaround, before the Lynx completely ran out of steam in the final minutes.
Pukki scored a penalty with four minutes to play, then Santeri Hostikka got in on the act in the 89th minute, and there was still time for Pukki to set up Alex Ring in stoppage time, as HJK turned what could have been an embarassing loss into a 5-1 rout in the space of 20 minutes.
Despite no wins in their previous eight, VPS were staying in the hunt for a top six place by drawing their most recent three games before Sunday's meeting with SJK, who could seal their Championship Round place with a point.
However, the form book went out the window with 29 minutes on the clock, as Tyler Reid set up Nicolas Fleuriau to put the Vaasa side in front. But the visitors regrouped at the break, and drew level seven minutes after the restart when Markus Arsalo teed up Ayo Obileye.
12 minutes from time, there was only going to be one match-winner for SJK - Kasper Paananen continued his fine form in front of goal, notching for the fourth game running to give the Seinajoki club a third win in four and the chance to stay in the hunt for the title and European places.
With KuPS moving second this weekend, the teams currently sat between second and fifth are separated by just four points, while Inter Turku lead by six with three rounds to play before the league splits into two.