勝利 and 敗北: who wins and loses
Identify the winning and losing sides and separate hoped-for outcomes from actual ones.
The winning side
勝利, read しょうり, means victory. 私たちのチームが勝利しました。 says that our team won.
勝利を目指しています。 means aiming for victory. It differs from an already achieved win.
The losing side
敗北, read はいぼく, means defeat. 相手のチームが敗北しました。 says that the opposing team lost.
敗北を認めました。 means acknowledging defeat. It is not a prediction of a future loss.
Contrasting outcomes
勝利を期待しましたが、結果は敗北でした。 says that victory was expected, but defeat was the result. Preserve the contrast between expectation and reality.
一度の敗北で全部が終わるわけではありません。 says that one defeat does not mean everything is over. It does not deny that the defeat occurred.
Does 勝利を目指しています mean victory has already been achieved?
Show the answer and why
No. It describes aiming for victory.