There are several synonyms for the phrase "lucky situation," including fortunate circumstance, stroke of good luck, fortuitous occurrence, happy opportunity, and serendipitous event. These phrases all convey a sense of unexpected good fortune or chance. Another synonym could be a favorable turn of events, indicating that circumstances have shifted in a positive direction. Alternatively, one might use the phrase "blessed happenstance" to emphasize the feeling of gratitude and divine intervention. Regardless of the wording chosen, these synonyms all express a sense of gratefulness for a good outcome that was not necessarily expected or planned for.