The stylish 32-year-old left-hander was 201 not out in a total of 327-2 a stumps on the first day of the match against Sussex at Derby.
His runs came off 271 balls with 22 boundaries.
STUMPS: #DCCC end the day 327-2, with Masood (201*) and Madsen (88*) to resume on Day Two. Here’s the moment Shan… https://t.co/Vq801vdZ6m
— Derbyshire CCC (@DerbyshireCCC) 1649955869000
Masood, who has played 25 Tests for Pakistan with a career best of 156, has been in a rich vein of form in the English tournament.
In Derbyshire’s opening match against Middlesex last week he made 91 and 62.