The second game of the series was tied in the bottom of the ninth, when Betts threw out Eduardo Escobar at the plate as he attempted to score from second on a single to right.

Chris Sale gave up five runs in four innings for the loss, including a steal of home by Lourdes Gurriel Jr. For the Red Sox, Mookie Betts and Mitch Moreland both homered, while Dustin Pedroia was 1-for-4 in his first MLB game since May 2018.

[52] In the second game of this two-game series, Boston starter Nathan Eovaldi held New York to three hits and one run through six innings, with the Red Sox leading, 3–1.

However, after the Yankees loaded the bases in the bottom of the seventh inning off of Red Sox reliever Brandon Workman, Brett Gardner hit a grand slam off of Ryan Brasier, giving New York a 5–3 lead and ultimately the win by that score.

In the second game of the series, the Red Sox jumped out to an early 5–0 lead, with four runs coming on a grand slam by Andrew Benintendi in the second inning.

Boston scored one run in the top of the ninth, helped in part by a pinch hit double by Michael Chavis in his first MLB at bat.

Boston closed the lead to 3–2 entering the ninth, but Detroit got an insurance run before closer Shane Greene notched his 11th save of the season in the 4–2 Tigers' win.

[57] In Saturday's game, Tampa Bay starter Charlie Morton held Boston to two hits and no runs through six innings, as the Rays went on to a 2–1 win.

A single then put runners at the corners, and Nicky Delmonico followed with a three-run walk-off home run off of Ryan Brasier, giving Chicago the win, 6–4.

There were no runs scored in the first two extra frames, with Jackie Bradley Jr. reaching over the outfield wall to prevent a game-winning homer by Trey Mancini in the bottom of the 11th.

[61] Andrew Benintendi hit a solo home run to give Boston a 2–1 lead in the top of the 12th, and Heath Hembree closed out the win with his first MLB save.

In the fifth inning, Boston tied the game, 3–3, on a Michael Chavis solo home run, followed by a Mookie Betts double and Bogaerts RBI single.

Boston lost the second game of the series, 10–3, after Toronto jumped out to a 6–0 lead through five innings, powered by DH Rowdy Tellez with two home runs for five RBIs.

The Red Sox tied the game in the fourth inning, on a solo home run by Xander Bogaerts and an RBI single by Sandy León.

In the final game of the series, Boston led the entire way, with New York drawing no closer than 3–2 at the end of the fourth inning, en route to an 8–5 Red Sox win.

Boston was unable to complete the sweep on Wednesday afternoon, as Chicago scored two runs in the top of the ninth inning via a José Abreu homer for an 8–7 win.

The loss, Boston's third in a row, left the team with a 44–40 record at the end of June, 11 games behind New York in the American League East standings.

Vázquez hit his 13th home run of the season, Chris Sale saw his record fall to 3–8, and Xander Bogaerts had a golden sombrero (four strikeouts) for the first time in his career.

[74] In the final game of the series, a nine-run sixth inning and a pinch hit home run by Marco Hernández in the ninth gave Boston an 8–7 win.

J. D. Martinez started at DH and was 0-for-2, Xander Bogaerts grounded out as a pinch hitter, and Mookie Betts appeared as a defensive replacement without batting.

Jackie Bradley Jr. hit a pair of three-run home runs; Rafael Devers, Mookie Betts, and Sandy León also homered.

[93] After retiring the Royals in order in the top of the 10th, Christian Vázquez hit a one-out double, which was followed by an intentional walk and then a game-winning single by Brock Holt.

The tie held until Mookie Betts hit his second home run of the game in the top of the 15th inning, which proved to be the difference as the Red Sox won, 7–6.

With expanded rosters allowed starting on September 1, the team added four pitchers (Jhoulys Chacín, Travis Lakins, Ryan Weber, and Héctor Velázquez) and two position players (catcher Juan Centeno and outfielder Gorkys Hernández).

[98] Following the end of the Triple-A season, on September 4 the team added four additional pitchers (Colten Brewer, Trevor Kelley, Bobby Poyner, and Mike Shawaryn).

The Red Sox had the tying run on base in the ninth inning, but Devers was thrown out at the plate trying to score on a two-out double that J. D. Martinez hit off of the Green Monster.

Following the September 8 loss to the Yankees, which dropped the Red Sox to 76–67 on the season, the team dismissed president of baseball operations Dave Dombrowski.

[99] The team announced that baseball operations would be run by assistant general managers Brian O'Halloran, Eddie Romero, and Zack Scott on an interim basis.

Boston won the final game of the series, 7–4, with Blue Jay starter and former Red Sox pitcher Clay Buchholz taking the loss.

† Minimum 3.1 plate appearances per team games played AVG qualified batters: Benintendi, Betts, Bogaerts, Bradley, Devers, Martinez, Vázquez