| 2026-04-14 | Barcelona | Clay | R32 | 2 | Carlos Alcaraz (1) | 130 | Otto Virtanen | 6-4 6-2 | H2H | 3 | 85 | 0 | 3 | 67.2% | 64.4% | 54.5% | 5/6 |
| 2026-04-01 | Bucharest | Clay | R32 | 136 | Daniel Merida | 123 | Otto Virtanen | 7-6(4) 5-7 7-5 | H2H | 3 | 171 | 4 | 4 | 61.2% | 63.3% | 46.0% | 7/13 |
| 2026-02-24 | Dubai | Hard | R32 | 25 | Tallon Griekspoor | 131 | Otto Virtanen | 6-3 6-4 | H2H | 3 | 74 | 6 | 2 | 59.3% | 80.0% | 66.7% | 0/0 |
| 2026-02-06 | Davis Cup WG1 PO: FIN vs HKG | Hard | RR | 116 | Otto Virtanen | 136 | Coleman Wong | 7-5 6-2 | H2H | 3 | 78 | 11 | 3 | 59.7% | 77.5% | 51.9% | 4/5 |
| 2026-02-06 | Davis Cup WG1 PO: FIN vs HKG | Hard | RR | 116 | Otto Virtanen | 262 | Siu Chi Nicholas Cheng | 6-0 6-1 | H2H | 3 | 42 | 9 | 0 | 54.5% | 83.3% | 66.7% | 0/0 |
| 2025-09-12 | Davis Cup WG1 R1: BUL vs FIN | Clay | RR | 992 | Alexander Vasilev | 141 | Otto Virtanen | 6-3 7-5 | H2H | 3 | 110 | 0 | 7 | 65.3% | 70.2% | 52.0% | 3/5 |
| 2025-06-09 | 's-Hertogenbosch | Grass | R32 | 101 | Otto Virtanen (WC) | 62 | Tomas Martin Etcheverry | 7-6(6) 7-5 | H2H | 3 | 143 | 7 | 3 | 58.4% | 77.8% | 43.8% | 1/4 |
| 2025-05-05 | Rome Masters | Clay | R64 | 9 | Lorenzo Musetti (8) | 130 | Otto Virtanen (Q) | 6-3 6-2 | H2H | 3 | 85 | 1 | 1 | 69.8% | 81.1% | 56.3% | 0/0 |
| 2025-05-05 | Rome Masters | Clay | R128 | 130 | Otto Virtanen (Q) | 72 | Hamad Medjedovic | 6-4 6-4 | H2H | 3 | 99 | 8 | 3 | 49.4% | 66.7% | 62.5% | 8/9 |
| 2025-03-31 | Marrakech | Clay | R16 | 51 | Roberto Carballes Baena (5) | 135 | Otto Virtanen | 6-4 6-4 | H2H | 3 | 80 | 1 | 0 | 77.6% | 66.7% | 61.5% | 2/4 |