Hirscher, who is aiming for a seventh successive World Cup title, extended his lead in the overall standings to 674 points, while he is also in the slalom's driving seat on 354 points.
Matt, the younger brother of Austria's former world champion and Olympic gold medallist Mario Matt, came close to snatching his second World Cup win after topping the opening leg 0.21 seconds ahead of second-placed Hirscher.
With the soft course on Mt Sljeme's artificial snow rapidly deteriorating throughout the second leg when the top 30 skiers started in reverse order, the front-runners showed their class amid a dramatic climax.
Kristoffersen, third after the opening leg, held on to stay in pole position ahead of Manuel Feller but could only watch helplessly as his great rival Hirscher did just enough to claim the lead by 0.11 seconds.
Matt appeared set to hand Hirscher a rare defeat after charging ahead by half a second at the intermediate point of the second leg, but holes in the lower section did the damage as he crossed the finish line 0.05 seconds behind Hirscher.
(Writing by Zoran Milosavljevic; Editing by Jeremy Gaunt)
