formidable
worthy opponent

But now it comes to the end, my worthy opponent.

He has not yet had a worthy opponent on the show.

"You have been a worthy opponent and friend," he said.

"I think next season most people will look at us as a worthy opponent," he said.

As each set eyes on the other, both knew they had finally met a worthy opponent.

This, she knew, would be an opponent more worthy of her skill.

Once set up, with a worthy opponent sitting across from you, this is a game that will eat your free time like none other.

Perhaps she will be a more worthy opponent than I expected.

It seemed she might make a worthy opponent after all.

If Bill's team won, they did so against a worthy opponent.