USA: Houston - Singles - Main
1/16-finals Nguyen D. Jung J. 0:2 (3:6, 2:6) details 13.11.2019
1/32-finals Sarkar S. Nguyen D. 0:2 (1:6, 0:6) details 12.11.2019
USA: Waco - Singles - Main
1/16-finals Nguyen D. Chappell N. CAN. details 16.10.2019
USA: Columbus 3 - Singles - Main
1/32-finals Nguyen D. Petit G. 1:2 (63 :7, 6:3, 4:6) details 16.09.2019
USA: Cary - Singles - Main
1/8-finals Nguyen D. Aragone J. 0:2 (3:6, 2:6) details 12.09.2019
1/16-finals Krueger M. Nguyen D. 1:2 (3:6, 6:3, 3:6) details 11.09.2019
1/32-finals Nguyen D. Sigouin B. 2:0 (6:1, 6:3) details 09.09.2019
USA: Winston-Salem - Singles - Qualification
Final Sarmiento R. Nguyen D. 2:0 (6:2, 6:3) details 18.08.2019
Semi-finals Nguyen D. Arevalo M. 2:1 (6:4, 4:6, 7:63 ) details 17.08.2019
USA: Memphis - Singles - Main
Semi-finals Cid Subervi R. Nguyen D. 2:1 (6:4, 4:6, 6:2) details 16.08.2019
Quarter-finals King K. Nguyen D. 0:2 (4:6, 3:6) details 16.08.2019
1/8-finals Caruana L. Nguyen D. 0:2 (4:6, 67 :7) details 14.08.2019
1/16-finals Peck J. Nguyen D. 0:0 RET. (3:5) details 13.08.2019
Canada: Winnipeg - Singles - Main
Semi-finals Schnur B. Nguyen D. 2:0 (6:2, 7:5) details 13.07.2019
Quarter-finals Nguyen D. Hoang A. 2:1 (7:65 , 4:6, 6:3) details 12.07.2019
1/8-finals Nguyen D. Couacaud E. 2:1 (1:6, 6:3, 6:2) details 11.07.2019
1/16-finals Soeda G. Nguyen D. 0:1 RET. (3:6) details 11.07.2019
1/32-finals Galarneau A. Nguyen D. 1:2 (6:1, 1:6, 5:7) details 10.07.2019
USA: Columbus 2 - Singles - Main
1/16-finals Nguyen D. Kwiatkowski T. S. 1:2 (6:4, 2:6, 4:6) details 11.06.2019
1/32-finals Nguyen D. Brouwer G. 2:1 (6:4, 65 :7, 7:5) details 10.06.2019
USA: Little Rock - Singles - Main
1/8-finals Shane R. Nguyen D. 2:1 (3:6, 6:3, 6:4) details 07.06.2019
1/16-finals Nguyen D. Peliwo F. 2:1 (4:6, 6:1, 6:0) details 05.06.2019
1/32-finals Nguyen D. King K. 2:1 (6:2, 65 :7, 6:3) details 04.06.2019
USA: Sarasota - Singles - Main
1/32-finals Nguyen D. Shane R. 0:2 (65 :7, 5:7) details 15.04.2019
China: Zhangjiagang - Singles - Main
1/16-finals Nguyen D. Giustino L. 0:2 (0:6, 3:6) details 19.03.2019
1/32-finals Banes M. Nguyen D. 0:2 (4:6, 3:6) details 18.03.2019
Japan: Yokohama - Singles - Main
1/16-finals Sugita Y. Nguyen D. 2:1 (2:6, 6:4, 7:5) details 26.02.2019
1/32-finals Ellis B. Nguyen D. 1:2 (6:3, 5:7, 5:7) details 25.02.2019
Mexico: Morelos - Singles - Main
1/32-finals Lopez Villasenor G. Nguyen D. 2:0 (6:3, 6:3) details 18.02.2019
India: Chennai - Singles - Main
1/32-finals Nguyen D. Altmaier D. 0:2 (3:6, 2:6) details 04.02.2019
Australia: Launceston - Singles - Main
1/16-finals Martinez P. Nguyen D. 2:0 (7:5, 7:62 ) details 29.01.2019
1/32-finals Nguyen D. Kelly D. 2:1 (6:3, 2:6, 7:5) details 28.01.2019
Vietnam: Da Nang - Singles - Main
1/16-finals Yang T. Nguyen D. 2:0 (6:3, 6:4) details 08.01.2019
1/32-finals Gabashvili T. Nguyen D. 0:2 (2:6, 4:6) details 07.01.2019
USA: M25 Los Angeles - Singles - Main
Quarter-finals Holt B. Nguyen D. 2:0 (6:4, 6:2) details 04.01.2019
1/8-finals Nguyen D. Lebedev A. 2:0 (7:64 , 6:4) details 03.01.2019
1/16-finals Gautier A. Nguyen D. 0:2 (1:6, 2:6) details 01.01.2019
Japan: Yokohama - Singles - Main
1/8-finals Nguyen D. Robert S. 0:2 (5:7, 0:6) details 01.03.2018
1/16-finals Nguyen D. Watanuki Y. 2:0 (6:2, 6:4) details 27.02.2018
USA: US Open - Singles - Qualification
Quarter-finals King D. Nguyen D. 2:0 (6:2, 6:1) details 23.08.2017
USA: Lexington - Singles - Main
Quarter-finals Nguyen D. Mmoh M. 0:2 (5:7, 1:6) details 05.08.2017
1/8-finals McGee J. Nguyen D. 1:2 (6:3, 3:6, 4:6) details 03.08.2017
1/16-finals Nguyen D. Statham J. R. 2:1 (1:6, 7:5, 6:4) details 01.08.2017
USA: Binghamton - Singles - Main
1/8-finals Nguyen D. Norrie C. 0:2 (3:6, 3:6) details 26.07.2017
1/16-finals Holt B. Nguyen D. 1:2 (3:6, 6:2, 3:6) details 25.07.2017