Fetching details from the dictionary...

to make war (on); to wage war (against); to go to war (with); to fight (with); to do battle (against)
to compete (against)
to struggle (against adversities, etc.); to fight; to contend; to resist
選手たちは最後まで闘い続けた。
The athletes kept fighting until the end.
病気と闘う彼女を応援している。
I'm cheering for her as she fights the illness.
偏見と闘うのは簡単なことではない。
Fighting prejudice is not an easy thing.