27‑Nov‑2023 | M15 Madrid | Hard | R32 | 1107 | 688 | (7)David Perez Sanz [ESP] d. Heinonen | 6-3 4-6 6-2 | | | | | | | | | |
6‑Nov‑2023 | M25 Heraklion | Hard | R32 | 1106 | 524 | Sidane Pontjodikromo [NED] d. (Q)Heinonen | 3-6 6-2 6-4 | | | | | | | | | |
23‑Oct‑2023 | M15 Heraklion | Hard | SF | 1265 | 299 | (1)Valentin Royer [FRA] d. (Q)Heinonen | 6-3 6-3 | | | | | | | | | |
23‑Oct‑2023 | M15 Heraklion | Hard | QF | 1265 | 419 | (Q)Heinonen d. (4)Guy Den Ouden [NED] | 7-6(4) 1-6 6-2 | | | | | | | | | |
23‑Oct‑2023 | M15 Heraklion | Hard | R16 | 1265 | 593 | (Q)Heinonen d. (7)Marlon Vankan [GER] | 6-2 2-0 RET | | | | | | | | | |
23‑Oct‑2023 | M15 Heraklion | Hard | R32 | 1265 | | (Q)Heinonen d. (Q)Graham Maassen [USA] | 6-4 6-3 | | | | | | | | | |
25‑Sep‑2023 | M25 Falun | Hard | R32 | 1268 | 473 | (6)Evgeny Karlovskiy [RUS] d. (Q)Heinonen | 7-6(6) 6-1 | | | | | | | | | |
18‑Sep‑2023 | M15 Danderyd | Hard | R32 | 1268 | 702 | (8)Jakob Schnaitter [GER] d. (WC)Heinonen | 6-2 6-2 | | | | | | | | | |
14‑Aug‑2023 | M25 Ystad | Clay | R32 | 1277 | 523 | (6)Marvin Moeller [GER] d. (WC)Heinonen | 6-2 6-7(4) 7-5 | | | | | | | | | |
31‑Jul‑2023 | M15 Hyvinkaa | Clay | R16 | 1358 | 786 | (4)Leonardo Rossi [ITA] d. (Q)Heinonen | 6-4 6-3 | | | | | | | | | |
31‑Jul‑2023 | M15 Hyvinkaa | Clay | R32 | 1358 | 1090 | (Q)Heinonen d. Niccolo Catini [ITA] | 6-1 6-2 | | | | | | | | | |
3‑Jul‑2023 | M15 Sofia | Clay | R16 | 1464 | 589 | (5)Denys Klok [RUS] d. (Q)Heinonen | 6-1 6-1 | | | | | | | | | |
3‑Jul‑2023 | M15 Sofia | Clay | R32 | 1464 | 1230 | (Q)Heinonen d. (Q)Sean Hess [ARG] | 5-7 7-5 7-5 | | | | | | | | | |
19‑Jun‑2023 | M15 Saarlouis | Clay | R16 | 1603 | 536 | (4)Matthew Dellavedova [AUS] d. (Q)Heinonen | 6-3 3-6 6-3 | | | | | | | | | |
19‑Jun‑2023 | M15 Saarlouis | Clay | R32 | 1603 | 639 | (Q)Heinonen d. Zura Tkemaladze [GEO] | 6-0 6-4 | | | | | | | | | |
15‑May‑2023 | M15 Kalmar | Clay | R16 | 1609 | | Max Dahlin [SWE] d. (WC)Heinonen | 6-3 2-6 6-4 | | | | | | | | | |
15‑May‑2023 | M15 Kalmar | Clay | R32 | 1609 | 1276 | (WC)Heinonen d. Arslanbek Temirhanov [SWE] | 7-6(1) 6-4 | | | | | | | | | |