The Argentine superstar sealed the Pichichi Trophy for a record seventh time in his illustrious career on Sunday as the Spanish top-flight season drew to a close following a hectic post-lockdown schedule.
Heading into the final day with the title already lost, Messi had only individual records in his sights as a depleted Barcelona squad travelled to Alaves.
The six-time Ballon d'Or winner led Real Madrid striker Karim Benzema by two goals in the standings ahead of that fixture, and moved decisively clear of his closest rival - who did not net for the champions in their subsequent 2-2 draw at Leganes - with a tidy brace in a thumping 5-0 triumph at Mendizorrotza.
In addition to notching a final total of 25 LaLiga goals in 2019/20, Messi also ended the season with a record-breaking 21 assists - one more than former team-mate Xavi managed during Barcelona's memorable 2008/09 treble-winning campaign under Pep Guardiola.
This is the fourth season in succession that Messi has finished as LaLiga's top scorer, while he was also top of the pile in 2009/10, 2011/12 and 2012/13.
This week, the much-loved 33-year-old revealed his frustration with Barcelona's shortcomings and passionately called for change.
Speaking after the thrashing of Alaves, Messi said: "We have said what we needed to say. We have spoken internally and been self-critical.
"There is nothing more to say, but to show the change."
Messi will hope to continue his sublime scoring run when Barcelona resume their Champions League campaign against Napoli next month.