first match; opening game; first round
Refers to the first match or game in a series, tournament, or competition. Often used in sports, games, and battles.
We ended up facing a strong team in our first match.
He gave it his all from the very first game.
He got off to a great start by winning the opening match with a comeback victory.
It became big news when the powerhouse team lost in their first match.
初戦 refers specifically to the first match in a competitive series, whereas 初回 is a broader term meaning 'the first time/episode/instance' used for many kinds of events, not just contests.
初戦 refers to the first match of a scheduled series or tournament, whereas 初陣 highlights the personal significance of one's very first challenge or battle.
初戦 is the first match of a series or tournament, while 最終戦 is the last one.
Compound of 初 (sho, 'first') and 戦 (sen, 'battle' or 'match'). The reading is on'yomi for both characters.
They safely got through the first round and advanced to the next stage.