2‑Nov‑1981 | Hong Kong | Hard | QF | 48 | | Marty Davis [USA] d. (8)Manson | 6-1 6-3 | | | | | | | | | |
2‑Nov‑1981 | Hong Kong | Hard | R16 | 48 | 54 | (8)Manson d. John Austin [USA] | 7-5 6-3 | | | | | | | | | |
2‑Nov‑1981 | Hong Kong | Hard | R32 | 48 | | (8)Manson d. Sashi Menon [IND] | 6-0 6-7 6-3 | | | | | | | | | |
26‑Oct‑1981 | Tokyo Indoor | Carpet | R16 | 53 | 47 | Mark Edmondson [AUS] d. Manson | 6-7(6) 6-4 6-4 | | | | | | | | | |
26‑Oct‑1981 | Tokyo Indoor | Carpet | R32 | 53 | 9 | Manson d. (4)Eliot Teltscher [USA] | 6-3 6-3 | | | | | | | | | |
19‑Oct‑1981 | Melbourne Indoor | Carpet | R16 | 47 | | Chris Johnstone [AUS] d. (6)Manson | 6-3 6-2 | | | | | | | | | |
19‑Oct‑1981 | Melbourne Indoor | Carpet | R32 | 47 | | (6)Manson d. Peter Johnston [AUS] | 6-0 6-3 | | | | | | | | | |
12‑Oct‑1981 | Sydney Indoor | Hard | R16 | 52 | 12 | (5)Vitas Gerulaitis [USA] d. Manson | 6-1 6-3 | | | | | | | | | |
12‑Oct‑1981 | Sydney Indoor | Hard | R32 | 52 | | Manson d. Sherwood Stewart [USA] | 6-3 6-4 | | | | | | | | | |
21‑Sep‑1981 | San Francisco | Carpet | R64 | 50 | 1 | (1)John Mcenroe [USA] d. Manson | 6-0 6-1 | | | | | | | | | |
1‑Sep‑1981 | US Open | Hard | QF | 74 | 17 | (15)Vitas Gerulaitis [USA] d. Manson | 6-4 6-2 4-6 6-1 | | | | | | | | | |
1‑Sep‑1981 | US Open | Hard | R16 | 74 | 5 | Manson d. (5)Jose Luis Clerc [ARG] | 6-3 7-6 6-3 | | | | | | | | | |
1‑Sep‑1981 | US Open | Hard | R32 | 74 | 11 | Manson d. (11)Peter Mcnamara [AUS] | 4-6 6-3 6-4 6-2 | | | | | | | | | |
1‑Sep‑1981 | US Open | Hard | R64 | 74 | | Manson d. Richard Meyer [USA] | 6-0 6-2 3-6 4-6 6-2 | | | | | | | | | |
1‑Sep‑1981 | US Open | Hard | R128 | 74 | | Manson d. Danny Saltz [USA] | 6-0 6-0 6-2 | | | | | | | | | |
17‑Aug‑1981 | Cincinnati | Hard | R32 | 81 | | (Q)Nduka Odizor [NGR] d. Manson | 1-6 7-6 6-2 | | | | | | | | | |
17‑Aug‑1981 | Cincinnati | Hard | R64 | 81 | 7 | Manson d. (3)Gene Mayer [USA] | 3-6 6-3 6-4 | | | | | | | | | |
10‑Aug‑1981 | Montreal / Toronto | Hard | R32 | 81 | 26 | (11)Tomas Smid [CZE] d. Manson | 7-6 3-6 7-6 | | | | | | | | | |
10‑Aug‑1981 | Montreal / Toronto | Hard | R64 | 81 | | Manson d. Jan Norback [SWE] | 7-5 6-0 | | | | | | | | | |
3‑Aug‑1981 | Columbus | Hard | R32 | 77 | | John Lloyd [GBR] d. Manson | 6-3 4-6 6-3 | | | | | | | | | |
22‑Jun‑1981 | Wimbledon | Grass | R128 | 73 | 8 | (8)Roscoe Tanner [USA] d. Manson | 6-1 6-4 6-4 | | | | | | | | | |
25‑May‑1981 | Roland Garros | Clay | R128 | 72 | 20 | (16)Eddie Dibbs [USA] d. Manson | 6-0 6-1 6-1 | | | | | | | | | |
18‑May‑1981 | Rome | Clay | R16 | 76 | 5 | (2)Ivan Lendl [USA] d. Manson | 7-5 6-2 | | | | | | | | | |
18‑May‑1981 | Rome | Clay | R32 | 76 | 47 | Manson d. Mario Martinez [BOL] | 6-4 7-6 | | | | | | | | | |
18‑May‑1981 | Rome | Clay | R64 | 76 | 66 | Manson d. Marcos Hocevar [BRA] | 2-6 7-6 7-6 | | | | | | | | | |
11‑May‑1981 | Hamburg | Clay | R64 | 69 | 88 | Klaus Eberhard [GER] d. Manson | 7-6 7-6 | | | | | | | | | |
13‑Apr‑1981 | Los Angeles | Hard | R32 | 67 | 72 | Nick Saviano [USA] d. Manson | 6-3 6-3 | | | | | | | | | |
6‑Apr‑1981 | Houston | Clay | SF | 83 | 70 | Sammy Giammalva Jr [USA] d. Manson | 6-7 6-4 6-3 | | | | | | | | | |
6‑Apr‑1981 | Houston | Clay | QF | 83 | 24 | Manson d. (7)Mel Purcell [USA] | 6-4 6-4 | | | | | | | | | |
6‑Apr‑1981 | Houston | Clay | R16 | 83 | 85 | Manson d. Paul Kronk [AUS] | 6-3 7-5 | | | | | | | | | |
6‑Apr‑1981 | Houston | Clay | R32 | 83 | 8 | Manson d. (2)Jose Luis Clerc [ARG] | 3-6 6-4 7-6 | | | | | | | | | |
23‑Mar‑1981 | Napa | Hard | SF | 71 | | (Q)Scott Davis [USA] d. (6)Manson | 7-5 2-6 6-4 | | | | | | | | | |
23‑Mar‑1981 | Napa | Hard | QF | 71 | | (6)Manson d. Tim Mayotte [USA] | 5-7 6-4 6-1 | | | | | | | | | |
23‑Mar‑1981 | Napa | Hard | R16 | 71 | | (6)Manson d. John Alexander [AUS] | 6-2 7-5 | | | | | | | | | |
23‑Mar‑1981 | Napa | Hard | R32 | 71 | | (6)Manson d. George Hardie [USA] | 7-6 6-7 6-0 | | | | | | | | | |
2‑Mar‑1981 | Denver | Carpet | QF | 78 | 4 | (1)Gene Mayer [USA] d. Manson | 6-4 6-4 | | | | | | | | | |
2‑Mar‑1981 | Denver | Carpet | R16 | 78 | 43 | Manson d. Tom Gullikson [USA] | 6-3 7-6 | | | | | | | | | |
2‑Mar‑1981 | Denver | Carpet | R32 | 78 | | Manson d. Chris Mayotte [USA] | 7-6 6-0 | | | | | | | | | |
23‑Feb‑1981 | Memphis | Carpet | R32 | 79 | 40 | Fritz Buehning [USA] d. Manson | 6-4 6-4 | | | | | | | | | |
23‑Feb‑1981 | Memphis | Carpet | R64 | 79 | 16 | Manson d. (9)Eddie Dibbs [USA] | 6-3 6-1 | | | | | | | | | |
16‑Feb‑1981 | La Quinta | Hard | R64 | 77 | 69 | Rod Frawley [AUS] d. Manson | 3-6 7-6 6-1 | | | | | | | | | |
2‑Feb‑1981 | Richmond WCT | Carpet | R32 | 75 | 10 | (5)Roscoe Tanner [USA] d. Manson | 7-6 6-3 | | | | | | | | | |
26‑Jan‑1981 | Philadelphia | Carpet | R64 | 74 | 10 | (6)Brian Teacher [USA] d. Manson | 6-3 7-5 | | | | | | | | | |
19‑Jan‑1981 | Monterrey WCT | Carpet | QF | 79 | 20 | (6)Vijay Amritraj [IND] d. Manson | 7-5 6-4 | | | | | | | | | |
19‑Jan‑1981 | Monterrey WCT | Carpet | R16 | 79 | 49 | Manson d. Butch Walts [USA] | 7-6 5-7 7-5 | | | | | | | | | |
19‑Jan‑1981 | Monterrey WCT | Carpet | R32 | 79 | 5 | Manson d. (1)Guillermo Vilas [ARG] | 7-6 6-4 | | | | | | | | | |