Evgeni Vasiukov (the victim of the famous "hippopotamus in the marsh" game) may not be the player he once was, but he's still pretty darned good. Although he is 81 years old, he still has a 2451 FIDE rating, and as such isn't a guy to be taken lightly. Of course, he can have his bad days - can't we all? - and when one's opponent plays as incisively as Miso Cebalo did in this game, disaster can strike.
(A P.S.: Vasiukov beat many great players, but to show that even in his older years he has remained a dangerous opponent check out this 2002 demolition job on Loek van Wely.)