BOSTON — Mookie Betts hit three home runs against James Paxton on Friday night during the first four innings of a 10-5 blowout of the Yankees, whose starting pitchers have stumbled this week in historic fashion.
Betts first homered on Paxton’s eighth pitch in a three-run first inning that included a two-run homer by J. D. Martinez. Betts went deep again leading off the third for a 4-0 lead and then hit a two-run drive in the fourth for a 7-0 advantage.
Betts added a run-scoring double in the sixth off David Hale to give him five R.B.I., and he grounded out in the eighth. With his fifth career three-homer game, Betts raised his season total to 18 homers.
Batters have had three-homer games on four straight days for the first time in big league history. Betts followed the Mets’ Robinson Cano, St. Louis’s Paul DeJong and Minnesota’s Nelson Cruz.
Andrew Cashner (10-5), coming off losses in his first two starts after Boston acquired him from Baltimore, allowed three runs and 10 hits in six and two-thirds innings.
Martinez drove in three runs for the Red Sox, who won the opener of the four-game series by 19-3 and have pulled within nine games of the division-leading Yankees. The Red Sox had 14 hits, giving them 37 in the first two games of the series, and reached 11 games above .500 for the first time this season at 58-47.
Paxton (5-6) became just the fourth pitcher in big league history to allow a leadoff home run in three straight starts, according to the statistics agency Stats, after Brad Radke (2004), Brandon Backe (2008) and Yovani Gallardo (2017). Colorado’s Charlie Blackmon went deep off Paxton to start a game on Sunday, and Tampa Bay’s Travis d’Arnaud did the same on July 15.
Paxton has an 11.00 earned run average in the first inning this year, allowing 10 first-inning home runs in 18 starts. Over all, he allowed seven runs and nine hits in four innings, including a career-worst four homers, while striking out nine and walking none. His E.R.A. rose to 4.72, and he has allowed 17 homers this season, including 11 in his last six starts.