at the first time和for the first time有什么区别

at the first time 是介词短语,是“在第一次” 强调顺序
for the first time 也是第一次,是个副词短语,在句子中做状语.强调首次
如：
He won the match at the first time.
他在第一次比赛中就获胜了.
We should inform his parents at the first time.
我们应在第一时间通知他的父母
For the first time I felt regret
我第一次感到后悔.