The origin of 破天荒 is a famous story from the Tang Dynasty (618-907 AD). In the Jingzhou region of China, no scholar had ever managed to pass the highest level of the imperial examinations (the jinshi, or进士). This long-standing failure was so well-known that people referred to the Jingzhou candidate list as the “heavenly wasteland” (天荒). When a scholar named Liu Rui (刘锐) finally passed, he “broke the heavenly wasteland.” The regional governor was so thrilled he offered Liu Rui a huge reward. However, Liu Rui modestly refused, stating he was merely the one who broke the ground, and that many more would follow.
破天荒 is a common and expressive idiom used in both written and spoken Chinese. It adds a layer of emphasis and surprise.