Carreira amadora
Club: Sentrum BK, Oslo, under legendary trainer Leif Hvalby, who was amateur champion and a sparring partner for the Danish EBU champion Christian Christensen in the 1950s and '60s.1981 Scandavian Junior Amateur heavyweight champion1984 Norwegian heavyweight championRepresented Norway as a Heavyweight at 1984 Los Angeles Olympic Games.Lost to Haakan Brock (Sweden) KO by 31985 Norwegian heavyweight champion1986 Norwegian heavyweight champion
Carreira profissional
Depois do boxe nos Jogos Olímpicos de Verão de 1984, Havnå se tornou profissional em 1986. Durante sua carreira, Havnå teve 22 brigas profissionais com 19 vitórias. Sua primeira luta foi uma decisão de quatro rodadas sobre o Johnny Nelson, do Reino Unido, que mais tarde também se tornou campeão mundial.
Registro de boxe profissional
Professional record summary22 fights19 wins3 lossesBy knockout112By decision81No.ResultRecordOpponentTypeRound, timeDateLocationNotes22Loss19–3

Roger McKenzieTKO6 (6)1993–02–12

Randers Hallen, Randers, Denmark21Win19–2

David JacoTKO4 (6)1992–03–14

Scandinavia Hotel, Copenhagen, Denmark20Win18–2

Greg GorrellKO1 (8)1991–12–06

Copenhagen, Denmark19Win17–2

Tyrone BoozeSD121991–02–15

Randers Hallen, Randers, DenmarkRetained WBO cruiserweight title18Win16–2

Daniel NetoUD121990–12–08

Aalborg Hallen, Aalborg, North DenmarkRetained WBO cruiserweight title17Win15–2

Boone PultzTKO5 (12) 2:451990–05–17

Nordjyske Messecenter, Aars, JutlandWon WBO cruiserweight title16Loss14–2

Boone PultzSD121989–12–03

Scandinavia Hotel, Copenhagen, DenmarkFor vacant WBO cruiserweight title15Loss14–1

Angelo RottoliTKO5 (12)1989–05–26

Bergamo, LombardyFor vacant European cruiserweight title14Win14–0

Lennie HowardTKO3 (8)1989–04–27

Skive Hallerne, Skive, Denmark13Win13–0

David MuhammedTKO6 (8)1989–02–16

K.B. Hallen, Copenhagen, Denmark12Win12–0

John WestgarthPTS81988–12–08

Sheraton Hotel, Copenhagen, Denmark11Win11–0

John WilliamsTKO4 (8)1988–10–28

Brøndby Hall, Brøndby, Denmark10Win10–0

Yves MonsieurPTS81988–05–15

K.B. Hallen, Copenhagen, Denmark9Win9–0

Roy SmithKO4 (8)1988–02–12

Helsingør Halln, Helsingør, Denmark8Win8–0

Alfonso RatliffPTS81988–01–15

Skive Hallerne, Skive, Denmark7Win7–0

Robert ObeyKO2 (?)1987–10–09

Aosta, Italy6Win6–0

Andrew GerrardPTS81987–10–02

K.B. Hallen, Copenhagen, Denmark5Win5–0

Stewart LithgoTKO5 (6)1987–03–28

K.B. Hallen, Copenhagen, Denmark4Win4–0

Mick QueallyTKO4 (6)1987–02–06

Herning Hallen, Herning, Denmark3Win3–0

Abner BlackstockTKO6 (6)1986–11–21

K.B. Hallen, Copenhagen, Denmark2Win2–0

Eddy VandenhouwelePTS41986–10–17

Randers Hallen, Randers, Denmark1Win1–0

Johnny NelsonPTS41986–10–03

Idrætshuset, Copenhagen, Denmark
Morte
Havnå morreu em maio de 2004 em Lindgrov, Risør, Aust-Agder em um acidente de barco aos 40 anos. O irmão de Magne Havnå, Erling Havnå, é um dos homens condenados por participar do assalto ao banco de nokas de 2004.
Veja também
List of world cruiserweight boxing champions