a blessing in disguise

US /ə ˈblɛsɪŋ ɪn dɪsˈɡaɪz/
UK /ə ˈblɛsɪŋ ɪn dɪsˈɡaɪz/
"a blessing in disguise" picture
1.

something that seems bad or unlucky at first, but later turns out to be beneficial

:
Losing that job was a blessing in disguise; it pushed me to start my own business.
The cancelled flight turned out to be a blessing in disguise, as we avoided a major storm.