I've been reading a book called With Arrow, Sword, and Spear: A History of Warfare in the Ancient World, by Alfred S. Bradford. It's not the best book I have ever read, but it is a nice overview of warfare from the ancient near east, to India, to China, to Rome, etc. I am toward the end of the book and on to the bits about early Roman empire. While reading last night, I came across something I had never heard before. The exact lines from the book are these:

In 43 Claudius led 50,000 troops in an invasion of Britain. He found allies, the legions performed admirably, and the conquest proceeded apace. Claudius, gimpy-legged, ill-coordinated, and not young, arranged somehow to kill the British chieftain in single combat and thus became one of the few Romans ever to win the spoila opima (awarded to a Roman commander who kills the enemy commander in single combat).

It seems unlikely to me that Claudius would 1) take on such a challenge, and 2) actually win with such physical limitations. Can anyone tell me what Professor Bradford's source is for this information, and furthermore, what your opinions are on this?