The victory in Thompson's third tour-level final late on Saturday night capped a dramatic week that saw him play for 12 hours across five matches.
His run included three match point saves in a comeback from 6-0, 3-0 down against Alex Michelsen in the quarterfinals, as well as a three-hour, 40-minute win against Alexander Zverev in the semis that finished after 1 a.m. Saturday morning.
In addition to his first title, Thompson will also be leaving Los Cabos with a career-best ATP ranking of 32.
Meanwhile, Ruud with his second loss this season and his first to a player outside the Top 25 this year denied a return to the Top 10 in the ATP Rankings for the first time since November.
Following his singles victory, Thompson got the better of Ruud for a second time on Saturday in the doubles' semifinals in Los Cabos.
The Australian teamed up with Max Purcell for a 7-6(1), 6-3 triumph against the Norwegian and his partner William Blumberg, allowing Thompson to become the first player since Nick Kyrgios (2022 Washington) to sweep the singles and doubles titles at the same ATP Tour event.
