The 1989 Stanley Cup playoffs, the championship of the National Hockey League (NHL) began on April 5, after the conclusion of the 1988–89 NHL season. This was the final year that all of the Division Semifinals began with teams playing the first four games in a span of five days. The playoffs concluded on May 25 with the champion Calgary Flames defeating the Montreal Canadiens 4–2 to win the Stanley Cup Final series four games to two.
The 1989 Stanley Cup playoffs featured two Canadian hockey teams, the Montreal Canadiens and the Calgary Flames. Montreal finished the regular season with 115 points, only two behind the league leader Calgary. They had last faced each other in 1986, with Montreal winning in five games. Calgary was only the second opposing team in NHL history to win a Stanley Cup at the Montreal Forum (the New York Rangers defeated the Montreal Maroons in 1928) and the first to do so against the Canadiens.
Flames defenceman Al MacInnis won the Conn Smythe Trophy as playoff MVP, while Lanny McDonald, who ended the regular season with exactly 500 goals, got his name on the Cup in his last ever NHL game. Flames co-owner Sonia Scurfield became the first Canadian woman to have her name inscribed on the Stanley Cup.
Wayne Gretzky and the Los Angeles Kings met the defending champion Oilers in the first round. The previous season saw the Oilers sweep the Boston Bruins in the Stanley Cup finals as Gretzky earned the Conn Smythe Trophy, setting playoff records for playoff assists, assists in a finals series and points in a finals series.
On August 9, 1988, the Oilers traded Gretzky to the Kings. The Gretzky-led Kings and Oilers (with many veteran super-stars) met in the first round of the Smythe Division playoffs. In seven games, Gretzky and the Kings defeated the defending Stanley Cup champions after falling behind 3 games to 1. In the second round Gretzky and the Kings were swept by the eventual champion Calgary Flames in four games.
Philadelphia Flyers goaltender Ron Hextall became the first netminder to shoot and score a goal in the playoffs, a shorthanded, empty-net score in Game 5 of the Patrick Division Semifinal against the Washington Capitals. One round later, Mario Lemieux torched the Flyers for an NHL-record five goals and eight points in a 10–7 Pittsburgh win in Game 5 of the Patrick Division finals. Hextall then made headlines in the Wales Conference Finals, attacking Montreal's Chris Chelios in the late stages of Game 6 as retribution for Chelios' unpenalized hit on Flyers forward Brian Propp in Game 1. Hextall received a 12-game suspension at the start of the 1989–90 NHL season for his actions.
Former Flyers head coach Mike Keenan led Chicago to the Campbell Conference finals in his first year behind the bench. The Hawks, with 66 points, had the fewest points of any playoff team that season (and tied in the overall standings with New Jersey, a fifth-place team in the Patrick Division), yet upset first-place Detroit and then St. Louis before bowing to Calgary.
(1) Calgary Flames vs. (4) Vancouver Canucks
Going into this series, many people[who?] expected that the Flames would defeat the Canucks in four or five games, due to Calgary having a 43-point edge in the regular season. Instead, Vancouver would take Calgary to seven games. The seventh game would go into overtime, both teams having great chances, the best being a breakaway for Canucks' captain Stan Smyl, only for Mike Vernon to make the save. Joel Otto scored the winner (via a deflection from his skate) with :39 left in the first overtime to send the Flames into the Smythe Division Final.
The Stanley Cup Final was decided between the two teams with the best records of the 1988–89 NHL regular season. Co-captain Lanny McDonald scored the second Flames goal in game six. This turned out to be the last goal in his Hockey Hall of Fame career, as he retired during the following off-season. Doug Gilmour scored two goals in the third period, including the eventual game and Cup winner to cement the victory for the Flames.
As of 2013, this is the most recent all-Canadian final.