Having gone down 3-2 against Ilves on the opening weekend, HJK were keen to bounce back in Seinajoki, but their hopes were dented in the 43rd minute when they were reduced to 10 men.
Santeri Hostikka scored twice early on against Ilves a week prior, but this time he notched a brace of yellow cards - the first for a poor challenge on Valentin Gasc, and the second for shoving Gasc back to the ground after he retailiated.
The visitors still probed in the second half, as Teemu Pukki hit the post, but cometh the hour, cometh Kasper Paananen, whose strike from the edge of the area wasn't the purest, but it found its way into the bottom corner nonetheless.
SJK sit second in the table after two 1-0 wins, as HJK sit second bottom, awaiting Pukki's impact.
KuPS' title defence began with a draw away at Inter Turku, but they got a victory under their belt on matchday two with a 1-0 win at home to AC Oulu.
The visitors put the champions under real pressure early on, hitting the bar and coming within a whisker of forcing an own goal.
However, midway through the first half, a half-cleared KuPS corner was headed back into the danger area and was eventually turned home by Agon Sadiku from close range.
Both sides peppered their opponents goal with chances throughout the rest of the game, and thanks to a second KuPS goal disallowed for offside, plus countless saves and clearances off the line, the score somehow stayed 1-0.
Top of the early standings are Ilves, who lead SJK on goals scored following a 2-1 success at home to new boys Jaro.
It looked to be a comfortable afternoon for the Tampere side, as they were two goals up after the first quarter of the match through Teemu Hytonen and Matias Rale.
But Jaro, who marked their top flight return with a 2-0 win on the opening day, managed to shut up shop and set up a nervy finish, when Kerfala Cissoko found the net with nine minutes to play.
They were unable to complete the comeback, meaning its the Lynx sitting atop the Finnish food chain for the time being.
The biggest win of the season so far went to Inter Turku, who beat Gnistan 3-0 at home.
The match was still in the balance late on, with Inter leading through Jussi Niska's first-half strike as the clock hit 89 minutes, before Oliver Pettersson turned the ball into his own net to give the hosts the points.
Dimitri Legbo put the icing on the cake in stoppage time, taking Turku to four points, while Gnistan are propping up the table.
Elsewhere, a 95th-minute equaliser from Tyler Reid rescued VPS a point in a 2-2 draw away from home, which denied KTP a first win since returning to the Veikkausliiga, while Mariehamn got off the mark, winning 1-0 at Haka courtesy of Emmanuel Patut's first-half goal.