1. He's definitely a dark horse in the competition, no one expected him to come out on top.
他绝对是比赛中的黑马，没人预料到他会脱颖而出。

2. The rookie player turned out to be a dark horse, surprising everyone with his skills.
这位新秀球员竟然成了黑马，用他的技术让所有人惊讶。

3. She may seem quiet, but she's actually a dark horse in the office, always exceeding expectations.
她看起来很安静，但实际上在办公室里是个黑马，总是超出预期。

4. The underdog team proved to be a dark horse in the tournament, defeating all their opponents.
这支弱势队伍在比赛中证明自己是个黑马，击败了所有对手。

5. The politician was considered a dark horse in the election, but he ended up winning by a landslide.
这位政治人物在选举中被认为是黑马，但最终以压倒性优势获胜。

6. The singer was a dark horse in the music industry, rising to fame unexpectedly with her unique voice.
这位歌手在音乐界是个黑马，以其独特的声音意外走红。