KuPS had managed to maintain perfect domestic form during their lengthening European campaign in recent weeks, but they finally dropped points for the first time in nearly two months after a draw with TPS, who now sit two points outside the top six.
Another victory looked inevitable when the home side went ahead midway through the first half when the ball was worked out to Saku Heiskanen on the left, and his deflected cross landed kindly for Joslyn Luyeye-Lutumba to turn home from close range.
Both sides had chances throughout the rest of the match, but while KuPS didn't do enough to put the game to bed, TPS didn't do enough to test Hemmo Riihimaki in the home goal.
That was until the 92nd minute, when KuPS failed to clear a pinballing ball from the edge of their area, allowing Pau Juvanteny to prod the ball through to Nils Veinbergs, who slotted the equaliser past Riihimaki to extend TPS' unbeaten run to two matches.
Yet KuPS' lead at the top remained five points after Inter Turku failed to capitalise at home against Lahti. Also in the midst of a European campain, the home side dominated with 19 shots but only three were on target, as Lauri Laine was guilty of missing a pair of big chances. FC Inter are at least two unbeaten in the league, while Lahti are seventh, ahead of TPS on goal difference.
AC Oulu's victory over Ilves last time out turned out to be a flash in the pan - their poor form returned with a narrow defeat to HJK. Mouhamed Gueye scored late in the first half to earn HJK a third victory in their last four in the league and move the Helsinki side into third, a point above Oulu, whose cushion to the sides in the bottom half is down to four points.
Ilves improved their chances of reaching the Championship Group by beating Mariehamn for a third win in their last four. Jardell Kanga set up Teemu Hytonen for the opener, before Kanga scored from the penalty spot in first-half added time to take the Tampere side within four points of the top half with three games to play, while Mariehamn are still without a win after 19 matches.