Alassane Plea had put the French side ahead but Kramaric's long-distance strike ensured that the points would be shared.
Rijeka sit at the bottom of Group I on just two points but that is only four behind their French opponents who occupy the second qualifying spot.
Jimmy Briand brought the first save from Rijeka goalkeeper Ivan Vargic but the Croats looked lively and Zoran Kvrzic and Leon Benko both saw shots miss the target.
It didn't take long for Lyon to take the lead, though, as Gael Danic's 14th-minute corner was headed back across goal by Yoann Gourcuff and Plea was on hand to finish from close range.
The lead was to last just seven minutes and the equaliser was one to savour with Kramaric unleashing a spectacular 30-yard effort which gave Mathieu Gorgelin absolutely no chance.
Briand was looking the most likely of the attacking players and he forced Vargic into a further save before Mate Males' block helped keep the scores level at the break.
Gourcuff should have doubled the lead six minutes into the second period but he could only fire over the bar when presented with a chance 12 yards out.
Lyon were having by far the better of the second half and Plea put a shot wide before Briand forced Vargic into another save from the edge of the box.
Despite the French side having the better of things, it was Rijeka who nearly nicked it at the death with Gorgelin having to make an impressive double save from Mehmed Alispahic and Benko.