noun
Refers to a contest between two opposing sides, often in sports or games. Emphasizes the competitive, head-to-head nature.
明日、隣町のチームと対抗戦がある。
Tomorrow we have a match against the neighboring town's team.
競技 refers to a sporting event or competition in a broader sense, not necessarily a direct head-to-head match.
Compound of 対抗 (opposition, rivalry) and 戦 (war, battle, match). The exact historical derivation is uncertain, but the combination naturally yields the meaning of a competitive match between two sides.