The Italians were heavily hit by injuries and made the trip with just 12 fit first-team players, meaning Simone Inzaghi had to rely on a number of youngsters to make up his squad.
Joaquin Correa opened the scoring inside a quarter of an hour. Felipe Caicedo intercepted as the hosts looked to build up from the back and Lazio were unforgiving.
After passes were exchanged around the edge of the box, Correa drifted centrally before picking out the corner with what he made look a simple finish.
But sloppy defending from Patric allowed the hosts to level. A quick corner caused panic in the Lazio box and although the spot-kick wasn’t initially awarded, the ball went dead 50 seconds later after Lazio had their own chance at the other end and VAR intervened.
Hans Vanaken stepped up and slotted to his right, sending Pepe Reina the wrong way.
Elsewhere in the group, Borussia Dortmund won 2-0 against Zenit Saint Petersburg to go within a point of top spot.