In the first set, Ruud took advantage of his first set point by making the break at 6-5. his task was easier in the second thanks to a break at 2-1. He then increased his advantage to 4-1, 5-2 and 6-3.
Ruud, finalist of the last two editions of Roland-Garros, won his 11th title in 22 finals, the 10th on clay and the first since that of Estoril, in Portugal, in April last year.
Tsitsipas, 25, who lost his first match of the year on clay, was playing his 29th final. His track record remains rich with 12 titles.