Fortuitous
/fɔːrˈtjuː.ɪ.təs/ adjective mediumHappening by lucky chance rather than by design or planning.
Their meeting at the airport gate turned out to be fortuitous, since he ended up hiring her on the spot.
Memory Trick
Fortuitous shares a root with 'fortune' — a fortuitous event feels like a stroke of good fortune landing in your lap by accident.