Alexander Semak began his hockey career in 1982 with the Ufa Salavat of the USSR. He played there for four seasons while also representing his country in the World Junior Championships winning gold in 1984, a bronze the next year, and gold once again in '86.
Semak spent the next five and a half seasons playing for the Moscow Dynamo and once again represented his country in countless tournaments such as Rendezvous '87, World and European Championships, the Canada Cup, and NHL-Soviet Super Series, collecting several medals and championships along the way.
After being selected by the New Jersey Devils in the 1988 Entry Draft, he made it to North America for the 1991-92 season where he played in 25 games. In his first full season with the team, 1992-93, Semak enjoyed a career year scoring 37 goals, 42 assists and collecting 79 points. He spent the next season and a half as a Devils before being traded to the Tampa Bay Lightning in 1995. Before the beginning of the next season, Semak was traded once again, this time to the New York Islanders, where he spent just one season.
The Vancouver Canucks claimed Semak in the Waiver Draft of 1996 but spent only 18 games with them before joining the Syracuse Crunch of the AHL for 23 games and then finishing the season with the IHL's Las Vegas Thunder. He joined the Chicago Wolves of the IHL for the 1997-98 season where he found his scoring touch once again, collecting 61 points in 67 games while winning the "Bud" Poile trophy as the playoff MVP with 27 points in only 22 playoff games.
The 1998-99 season saw Semak play with the AHL's Albany River Rats before leaving North American hockey to play in Germany for his last season as a player.