1989–90 Porin Ässät season

The 1989–90 Porin Ässät season was the club's first and only season in the I-Divisioona and the second highest league in Finland. Ässät was relegated after the previous SM-liiga season. Ässät crushed I-Divisioona records and was promoted back to the SM-liiga after just one season.

Relegation to the I-Divisioona for the 1989–1990 season, however, raised the hockey boom in Pori, as the townspeople stood behind their team. Audience numbers increased from previous SM-liiga seasons when Ässät's games were watched with interest. For the I-Divisioona season, Ässät got top reinforcements when Arto Javanainen returned from TPS and Arto Heiskanen from Lukko. Aleksei Frolikov and Vladimir Durdin came from Riga Dynamo. Matti "Mölli" Keinonen became the coach. The visit to the I-Divisioona only lasted a season. Ässät was superior in the regular season, breaking numerous I-Divisioona records and easily progressing to the series win and SM-liiga qualification. In the SM-liiga qualifiers, Ässät faced JoKP. Ässät won the series 3–0 and returned to the SM-liiga.

Regular season and promotion
Ässät's regular season started with a 10–2 home victory against Kiekko-Espoo. Ässät won the next four games, before a 3–3 tie game with FoPS. Ässät's first loss came in January 1990 after a 27 game unbeaten streak. Ässät managed to only lose four games out of the 44 game season and tie three times. Some of the biggest victories for Ässät included 19–4 against Ketterä, 19–3 against Sport, 20–6 against Ketterä again and 13–0 against KooVee. Ässät's top point scorer was Arto Heiskanen with 110, a I-Divisioona record. Arto Heiskanen also recorded a +/- statistic of +90.

Ässät finished 1st in the regular season, winning the I-Divisioona championship. Ässät faced JoKP in the SM-liiga qualification series. Ässät won the series 3–0 and got promoted back to the SM-liiga.

Skaters
Top-10 point scorers of the season. Sorted by points, then +/-.