also: よいぐあいに
Used when something turns out well by chance or in a favorable way. Often implies a pleasant coincidence or a good outcome that wasn't entirely planned.
See also: 具合
いい具合にバスがすぐ来た。
Luckily, the bus came right away.
いい具合に天気が回復した。
Happily, the weather cleared up.
幸い is a more formal or literary way to say 'fortunately', often used in writing or polite speech.
Standard spelling with the common reading いいぐあいに.
More formal or written variant using 良い and the reading よいぐあいに.
Search-only form; the same reading as 良い具合に but with よい in kana.
A phrase composed of いい (good) + 具合 (condition, state) + に (adverbial particle), literally 'in a good condition/state', which developed the adverbial meaning 'luckily, happily'.