If this question asking whether or not Grendel fears Beowulf at any point in the entire narrative, then the answer has to be yes.
no hand-grapple greater
The monster is amazed at Beowulf’s strength.
In any man else had he ever encountered:
Fearful in spirit, faint-mooded waxed he,
Not off could betake him; death he was pondering,
He is anxious to flee.
Would fly to his covert, seek the devils’ assembly:
We know that Grendel comes into the hall supremely confident in his ability to continue wreaking the havoc that he has been doing for months. Everybody fears Grendel, and he leaves a trail of bloody bodies in his wake night after night. Because of his battle prowess, he has no reason to fear this new warrior before him; however, Grendel quickly realizes that Beowulf is a man with extraordinary strength, and that scares Grendel. He has finally met an opponent that causes him to think...
(The entire section contains 2 answers and 473 words.)