The Russian, who defeated three Frenchmen in Marseille to reach the championship match at the ATP 250 event, has now captured nine tour-level crowns, improving his record in finals on indoor hard courts to 5-0.
"All the battles I have had with Felix since the first time back in 2018 have had drama," Rublev said in his on-court interview. "All have had at least one set that went 7-6 and now he is one of the greatest players. Especially this season, he is on top now.
It was a pleasure to share a court with him and have an amazing final like this." Since triumphing in Rotterdam last March, Rublev had lost finals at ATP Masters 1000 tournaments in Monte Carlo and Cincinnati and on grass in Halle, an ATP 500 event.
However, the second seed ensured he would not suffer the same heartache against Auger-Aliassime. Rublev demonstrated his impressive mental strength in the championship match.
The Russian rallied from a break down in the first set and recovered from failing to serve out the clash at 5-4 in the second set.
He then saved a set point on serve at 5-6, 30/40 in the second set to eventually triumph after one hour and 57 minutes.