nick-of-time 

The act of something happening in that exact moment. exactly, just in time

i ducked just in a nick-of-time to see a blue panda smack the wall exactly where my head had been a second ago.

nick-of-time by samllas October 23, 2008

In the nick of time 

At the last possible moment.
Just at the critical moment.
Just in time.

The beautiful woman was saved just in the nick of time as some man untied her from the train tracks. She later gave him the best head ever.

In the nick of time by Dancing with Fire December 28, 2010