Tuesday, October 3, 1989, at Oakland–Alameda County Coliseum in Oakland, California The A's went off as heavy favorites largely due to their status as defending American League champions.

Then, after Tony Phillips reached with one out, Blue Jays manager Cito Gaston pulled Stieb and replaced him with the recently acquired Jim Acker.

Phillips stole second and stayed on an infield single by Mike Gallego, and Acker then hit Rickey Henderson with a pitch to load the bases with one out.

Needing a double play to get out of the inning, Acker did his job by inducing Carney Lansford to ground to Fernandez.

Wednesday, October 4, 1989, at Oakland–Alameda County Coliseum in Oakland, California Game 2 saw the A's throw their number two starter, Mike Moore, against the Blue Jays' Todd Stottlemyre.

Acker then gave up a double to Dave Henderson and a single to Tony Phillips that scored two more runs and made it a 5–1 Oakland lead.

Gaston pulled Acker and replaced him with David Wells, who got the final two outs of the inning, but the game was for all intents and purposes over.

The steal of third elicited a reaction from Blue Jays third baseman Kelly Gruber when Henderson walked the last several steps to the base because the catcher didn't throw.

The A's countered by bringing in Dennis Eckersley, who minimized the damage by yielding a one-run single to McGriff and then giving up another run on a double play.

Moore was the winning pitcher, Stottlemyre the loser, and Eckersley got his fifth save in his last five chances in the ALCS dating back to 1988.

When Ernie Whitt singled, Fernandez scored to give the Jays the lead and bring the crowd back into the game cheering wildly.

Honeycutt gave up singles to two light-hitting Blue Jays, Manuel Lee and Junior Felix, scoring Tony Fernández and loading the bases with only one out.

Gene Nelson relieved Honeycutt and gave up a single to right by Wilson that scored Lee, but a great throw from Canseco nailed Felix at the plate.

Toronto could guarantee a return of the series to Oakland with a win while the A's would gain a significant lead of three games to one if they prevailed.

Rickey Henderson, who was 3 for 8 with four walks, five runs scored, and seven stolen bases, drilled a two-run homer to give the A's a 2–0 lead.

After Flanagan retired Dave Henderson, José Canseco secured the most memorable moment of the series by socking the first home run ever hit into the fifth-tier upper deck of the SkyDome.

The Toronto crowd sat in stunned silence as Canseco circled the bases; the home run was measured at 480 feet (150 m).

The Blue Jays got that run back in the bottom of the inning when Tony Fernández doubled and scored on pinch-hitter Pat Borders' single.

Eck induced a fielder's choice ground out by Wilson that scored Lee then faced 1989 home run champion Fred McGriff, who had not hit a homer in more than a month.

McGriff won the battle, lining a single to center field that scored Wilson, but when Eckersley got George Bell to pop up for the third out, the A's still led by one with just an inning to play.

In the bottom of the ninth, Eckersley gave up a single to Kelly Gruber but otherwise retired the side, getting pinch-hitter Lee Mazzilli to pop out to end the game.

The end result was a 4–3 win for the A's and a return trip to the Fall Classic to face their Bay Area neighbors, the San Francisco Giants.

Henderson again walked—his seventh of the Series—and again stole second—his eighth stolen base of the Series—and came home on Canseco's single to give the A's a 1–0 lead less than four minutes into the game.

Stieb got the hook and Jim Acker got out of the inning, but not before McGwire scored on a squeeze bunt by Mike Gallego.

1989 ALCS (4–1): Oakland Athletics over Toronto Blue Jays Rickey Henderson was the unanimous choice for Most Valuable Player.

The only thing Henderson did wrong the entire series was commit an error in Game 4, and the recipient (George Bell) failed to score.

The one Blue Jay who had a very good series was Tony Fernández, who hit .350, scored six runs, and stole five bases in a losing cause.