BALTIMORE—Zach Eflin has had an outstanding first three weeks with the Orioles, and on Thursday night, he became the first pitcher in team history to win his first four appearances as a starter.

Eflin allowed one run on five hits in six innings, striking out a season high eight batters without a walk as the Orioles beat the Boston Red Sox, 5-1, before 25,445 at Camden Yards.

Eflin (9-7) was acquired from Tampa Bay on July 26^th and has beaten Toronto, Cleveland, the Rays, and now Boston (63-57). He threw 87 pitches and gave up Wilyer Abreu’s 14^th home run in the fourth. Abreu’s home run landed on Eutaw Street.

The Orioles (72-50) are tied with the idle New York Yankees for first in the American League East.

Manager Brandon Hyde turned to Gregory Soto, hoping for a strong seventh. Soto hit Red Sox designated hitter Masatska Yoshida with his first pitch, struck out pinch-hitter Danny Jansen and allowed a single to Ceddanne Rafaela before he was lifted for Burch Smith.

Pinch-hitter Romy Gonzalez hit into a double play on Smith’s third pitch. The Orioles also turned a double play in the ninth.

Cionel Pérez and Yennier Cano each pitched scoreless innings in the eighth and ninth.

Nick Pivetta (5-8), who had won eight of his first 10 decisions against the Orioles, allowed three runs on five hits in five innings.

Gunnar Henderson hit his 31^st home run, a two-run shot, his second in as many nights to give the Orioles a 2-1 lead. Cedric Mullins hit his 13^th to lead off the fifth.

The Orioles scored against Bailey Horn in the sixth on a leadoff double by Anthony Santander and an RBI single by pinch-hitter Ryan Mountcastle.

Colton Cowser’s RBI double against Chase Shugart scored James McCann in the seventh to give the Orioles a 5-1 lead.