You nearly nailed it, Purdy did throw for 4 TDs and 0 INTs and Dak did have 1 TD, except he had 3 INTs.
But thinking the Cowboys would win when it's 4-0 and 1-1 is pretty ridiculous so you were way off on that part.
49ers 42
Cowboys 10
It happened two weeks ago.
Kirk Cousins threw for 4 TD's and no INT's.
Hurts threw for one TD and one INT.
The Eagles won.
It happened another time during week #6 in the 2020 season between the Saints and Chargers.
Herbert threw for 4 TD's and 0 INT's
Brees had 1TD and 1 INT
The Saints won.
It has happened at least two more times since 2000.