Mannarino broke for 1-0 in a gruelling 6 minute game, then held for 4-2 saving all five break points before clinching 6-4.
Rublev broke for 2-0 in a deuce game and held for 5-2 saving both break points, sealing 6-3 with clinical precision.
Mannarino broke for 5-3 and held for 6-3 in a deuce finish, taking the set after Rublev saved one break point for 3-3.