Chapman's walk off double off the centre field wall gave the Blue Jays a 3-2 win to complete a three-game sweep of the Boston Red Sox (74-76).
"It's kind of been how this whole year has been," Chapman said. "A lot of ups and downs for us. To get swept, then sweep somebody.
"With how precious all these wins are, it was nice that we're able to flush that Texas series."
With a dozen games remaining in the regular season, the Blue Jays hold an American League wild-card spot after Cleveland swept the Rangers and the Seattle Mariners were swept in their three-game set with the Los Angeles Dodgers.
Toronto holds the second wild-card berth, with Texas in third a half game back. The Mariners sit fourth, one game back of the Rangers and 1 1/2 games behind the Jays.
The level-headed Chapman was not immune to the recent roller-coaster ride. As he attempts to regain his form after time on the injured list because of a troublesome left middle finger, manager John Schneider sent Cavan Biggio to pinch-hit in Chapman's place in the ninth inning on Saturday.
Biggio delivered with a single and wound up scoring the tying run.
"I've helped this team win a lot of games," Chapman said. "I have no ego, so I'm OK with the decision."
Chapman's hit off reliever Garret Whitlock (5-5) gave the Blue Jays their sixth win in a row against Boston after dropping the first seven games against their AL East rivals earlier in the season.
The game-winning hit scored Biggio, who reached base with a one-out single before 41,876 at Rogers Centre.
"I love the fact (Chapman) got the hit today," Schneider said. "I think (Toronto pitcher) Chris Bassitt said it yesterday. We have the guys, and he's one of them.
"So hopefully, today is a good little stepping-stone for him."
The Blue Jays led 1-0 after the second inning and 2-0 after Daulton Varsho's solo shot to right field with one out in the fifth.
Biggio reached safely in the second inning with an infield hit up the middle with one out. He advanced to third base on Chapman's double down the left-field line and scored on Kevin Kiermaier's sacrifice fly to left field.
Canadian starter Nick Pivetta was on the hook for both runs. But the Victoria righty lasted 6 1/3 innings, yielding only four hits with six strikeouts and a walk.
In the span between the Chapman double and Varsho homer, the 30-year-old Pivetta did not surrender a hit and retired nine of 10 Blue Jays.
Toronto lefty Hyun Jin Ryu pitched 4 2/3 innings of shutout ball, giving up six hits with two strikeouts and a pair of walks on 83 pitches.
He proved masterful in escaping jams. In the second and third innings, the Red Sox had runners on second and third with no outs, but Ryu rallied for three consecutive outs on both occasions.
He also left a Red Sox runner at third base in the fourth with an inning-ending double play.
Boston left 12 runners on base and batted 1 for 14 with runners in scoring position.
Refsnyder scored on Reyes's single to centre.
This report by The Canadian Press was first published Sept. 17, 2023.
Tim Wharnsby, The Canadian Press