I 〔透き間〕a gap
the gap between the wall and the pillar
He made his way through the crowd.
The two became estranged.／Their relationship cooled.
It only patched up their differences for the moment.
The distance between the two men steadily increased.
catch ((a person)) off guard／take advantage of ((a person)) at an unguarded moment
He caught the other candidate off guard and got a foothold in his territory.