Translation:They came first in the previous soccer competition.
"They came in first..." or "They came in first place..." is used colloquially in the US. As is "football" outside of the US.
The English is distinctly British, and in American English "they came first" is never correct, it must be "they came in first" - due to the available words in the word bank, I wrote "They came in first the previous soccer competition." which yes, is wrong, but the "correct" answer is also wrong. In addition, when talking about soccer, it should be a "match" or "game" not "competition." 比赛 can also mean these.