Shouldn't Goku say "strongest" then, were Yajirobe the strongest he has ever met?
The fight was pretty short, actually. It consisted basically of Goku attacking Yajirobe, both their arms clashing, Goku defending himself from Yajirobe's hits, getting headbutted, whining a bit and then headbutting Yajirobe back, who faked being hurt and tried to kick Goku, who dodged, punched Yajirobe in the face and kicked him in the rocks, who came out basically unharmed. It wasn't a back and forth fight with both exchanging punches evenly. Maybe the anime added something else that I can't possibly remember without consulting it.