Conversation so far:
What was a goal Lionel Messi broke this year?
on 20 March, Messi became the top goalscorer in Barcelona's history at 24 years old.
who did he play for?
Barcelona.
how many goals did he score to break the record?
overtaking the 57-year record of Cesar Rodriguez's 232 goals with a hat-trick against Granada.
how old was he when he broke the record?
24 years old.
did the team do well this year?
the team had lost the league to Real Madrid and was eliminated in the Champions League semi-finals.
who was their coach?
CANNOTANSWER.

Question: who did he beat to earn the record?
Self-contained rewrite: who did  Lionel Messi beat to earn the top goalscorer record?