| 18‑Oct‑2021 | Antwerp | Hard | SF | 32 | 16 | (1)Jannik Sinner [ITA] d. (7)Harris | 6-2 6-2 | | 0.57 | 3.3% | 3.3% | 65.6% | 55.0% | 33.3% | 3/7 | 1:26 |
| 18‑Oct‑2021 | Antwerp | Hard | QF | 32 | 39 | (7)Harris d. Marton Fucsovics [HUN] | 6-2 7-5 | | 1.33 | 13.8% | 1.7% | 69.0% | 82.5% | 44.4% | 1/2 | 1:25 |
| 18‑Oct‑2021 | Antwerp | Hard | R16 | 32 | 50 | (7)Harris d. Jan Lennard Struff [GER] | 6-2 6-3 | | 1.63 | 25.0% | 2.3% | 65.9% | 82.8% | 53.3% | 0/0 | 1:10 |
| 18‑Oct‑2021 | Antwerp | Hard | R32 | 32 | 186 | (7)Harris d. (WC)Zizou Bergs [BEL] | 7-6(4) 6-3 | | 1.78 | 14.3% | 3.2% | 61.9% | 84.6% | 79.2% | 3/3 | 1:26 |
| 19‑Oct‑2020 | Antwerp | Hard | QF | 90 | 38 | Ugo Humbert [FRA] d. (Q)Harris | 6-3 7-6(2) | | 0.68 | 8.8% | 0.0% | 70.2% | 75.0% | 35.3% | 4/6 | 1:35 |
| 19‑Oct‑2020 | Antwerp | Hard | R16 | 90 | 28 | (Q)Harris d. (7)Taylor Fritz [USA] | 7-5 7-6(3) | | 1.33 | 16.0% | 0.0% | 74.7% | 82.1% | 47.4% | 3/3 | 1:53 |
| 19‑Oct‑2020 | Antwerp | Hard | R32 | 90 | 74 | (Q)Harris d. Corentin Moutet [FRA] | 7-5 6-2 | | 2.21 | 14.3% | 4.1% | 67.3% | 84.8% | 68.8% | 1/2 | 1:24 |
| 19‑Oct‑2020 | Antwerp | Hard | Q2 | 90 | 86 | (5)Harris d. (3)Federico Coria [ARG] | 6-4 6-0 | | 2.01 | 17.0% | 0.0% | 59.6% | 92.9% | 52.6% | 0/0 | 1:01 |
| 19‑Oct‑2020 | Antwerp | Hard | Q1 | 90 | 1005 | (5)Harris d. (WC)Zane Khan [USA] | 7-6(1) 6-2 | | 1.41 | 10.5% | 3.5% | 71.9% | 73.2% | 68.8% | 2/3 | 1:14 |
