'tough rival' is correct and usable in written English.
You can use it to describe someone who is a hard competitor. For example, "Although my team lost the game, our tough rival put up a great fight."
"The last two games we played a tough rival game, then at DePaul, they played well and we just struggled".
"That effectively means they have to beat Samsung, which is a very tough rival," said Nobuo Kurahashi, an analyst at Mizuho Investors Securities in Tokyo.
"That's something you expect when you're playing a tough rival and somebody that has a very similar style of game that I have," he said.
The old man and his family are the obvious favourites, but a tough rival family, led by a toothless, cocksure man called Carver, is also in the running.
Apawamis, the Westchester district champion, won from New Canaan, 8½ to 6½, but it wasn't enough to overtake its tough rival, Round Hill, the leader last week.
Vettel said he expected Webber to continue to be a tough rival for the rest of the season.
"But I still have very tough rivals.
Yet for all of Mr. Shim's optimism about "Prince of Egypt," it faces tough rivals.
"We're going to face very tough rivals with impressive players like Ronaldinho but we have a very united team.
With both sides remarking on the professionalism of the other, the tenor of the negotiations reflected the difficult competitive realities that have domestic manufacturers and their labor unions fighting for survival against tough rivals.
To maintain their spot in the West against tough rivals, the Blues will want to start finding a few more goals, but for now the formula seems to be working.
