「日本×コロンビア」って英語でなんて言うの？

It is simply put like this in writing. In conversation, you would also hear "It's Japan against Colombia" or "Japan and Colombia are playing". It depends on the context and how long the conversation is.
"Which match?"
"Japan VS Colombia"

"Who's playing?"
"Japan and Colombia"

When two teams are competing against each other we use the word versus or the abbreviation 'vs.'. You will see and hear this word a lot when watching a game in English or reading about a game in English. We also use this word in our everyday conversations. I hope this explanation and these two sentences help you out!

Yes, it could be said that every game, match or contest is a battle or "Nikkansen" and sometimes in the UK, commentators do talk about 'head to head battles' or head to head confrontation.' There is also the phrasal verb: to go head to head with someone/another team.
Alternatively, it may be described a s contest in some situations :
"The contest between Ali and Frasier was much anticipated."

▪ Japan Vs China
Vs = Versus
This means Japan is playing against China.

▪ Japan against USA
This indicates that Japan is having a competition match against USA.

"Japan VS Colombia" VS is short for versus- so Japan will be playing Colombia in the match

"A match between Japan and Colombia" This is another way of explaining that the two teams will face each other in a match.

"Japan and Colombia are playing tomorrow" This explains that the two teams will be playing against each other in the match tomorrow.

When you're writing about two competing teams in sports, you would usually use the following format: Japan vs. Colombia

VS = versus
Versus also means against. So when you speak, you can say the soccer match is Japan against Colombia

*Japan vs Colombia -Vs is an abbreviation for versus.

*Japan against Colombia - Simply means team Japan is playing against team Colombia