A critical moment or decisive juncture when the outcome is at stake; a do-or-die situation.
明日の試験は正念場だ。頑張らないと合格できない。
Tomorrow's exam is the critical moment. If I don't try hard I won't pass.
会社の存続がかかった正念場で、彼は重要な決断を迫られた。
At the do-or-die moment for the company's survival, he was forced to make an important decision.
この試合がチームにとっての正念場だ。集中して戦おう。
This match is the team's decisive moment. Let's focus and fight.