Rufus is not the most physically durable of the group but he knows how to compensate with his smarts & quick reflexes/reaction time. He could win a fight like this. Which could be an interesting (needed) challenge for Elena.
She's smart but her overeagerness causes her to do bad mistakes in combat ( the Elena knuckle is almost worthless due to the time she takes to charge the attack & she misses to the point of falling down cliffes, she sometime need to take a breath because she doesn't spend her energy correctly etc)
So fighting someone like Rufus might push her to think a bit more beforec acting to win, which could be a valuable learning experience for the both of them.