The 1989 season was marked by the arrival of Ablett's third coach, former North Melbourne Brownlow Medallist Malcolm Blight. Ablett helped the Cats reach the finals on the back of a ten match winning streak to end the regular season. In a 134-point victory against Richmond, Ablett scored 14 goals, breaking a 22-year club record, and moving club legend and former club premiership coach Bobby Davis to laud Ablett as the equal of the legendary Graham 'Polly' Farmer, the finest footballers he had seen at Geelong. His season lowlight occurred in Round 12 when he was suspended for 3 matches after he controversially felled the Melbourne captain, Gary Lyon behind the play.
Against the reigning premiers Hawthorn in the 1989 VFL Grand Final, Ablett asserted himself from the opening bounce, leading out from full forward, marking the first centre clearance kick and slotting through the game's first goal. By half-time, Ablett had kicked four goals, but the Cats trailed at the main break by 37 points. Ablett kicked a further five goals in the second half, which saw an injury-depleted Hawthorn's lead reduced to just 6 points with less than a minute to go. However, the Cats fell short, and Hawthorn held on to defeat Geelong in one of the toughest grand finals of the modern era, winning by 6 points. Ablett's performance in kicking 9 goals earned him the Norm Smith Medal, and in doing so became only the second member of the losing team in VFL/AFL history to be awarded the honour – a performance regarded by many as unrivalled on football's biggest stage. Ablett's 9 goals also saw him equal Gordon Coventry's goals record set in the 1928 Grand Final.
Ablett combined strength, speed, and skill to produce many spectacular highlights and goal-kicking feats. A noted big game player, Ablett kicked 43 goals in 11 State appearances. More significantly, he booted 64 goals over the course of his 16 finals – an average of four goals a game. His haul of 27 goals in the 1989 finals series is a record that still stands. He was awarded the Norm Smith Medal for his performance in the 1989 Grand Final, where he was adjudged best player afield. In doing so, he became one of only four players (the others being Maurice Rioli −1982, Nathan Buckley −2002, and Chris Judd −2005) to win the medal playing for the losing side. In 1996, Ablett joined Gordon Coventry, Doug Wade, Jason Dunstall and Tony Lockett as the only players in league history to kick 1000 VFL/AFL goals.