|Born||24 December 1971
|Height||5'9" (175 cm)|
|Highest ranking||No. 57 (25 June 1990)|
|Grand Slam Singles results|
|Australian Open||2R (1992)|
|French Open||3R (1990)|
|US Open||1R (1990)|
Rahunen was the 1989 winner of the Under-18s European Junior Tennis Championships, held in Prague.
He performed well in the 1990 ATP Tour, reaching quarter finals at Stuttgart, Umag and Båstad. In Stuttgart he defeated top 50 players Javier Sánchez and Amos Mansdorf, both in straight sets. He was also a semi finalist at the Florence Open that year and reached the third round of the 1990 French Open.
|No.||Year||Tournament||Surface||Opponent in the final||Score in the final|
|1.||1989||Hanko, Finland||Clay||Andres Vysand||6–2, 6–0|