lion is really powerfull and really fast but grizzly bear maybe be mor powerful than lion.but lion can fight with even with a big grizzly bear but it is too dangerous for both and im think after few minutes both are tierd and stop fight and both can be winner in different times.but important thing is that both are too powerfull and beautifull and there is no promblem if the lion be loser or winner or bear be winner or loser,both can be winner but a polar bear can be winner in fight between grizzly bear or lion and i dont think lion or grizzly bear can be winner but no matter.all of them are wonderfull and beautiful and this is impotrant thing.