Renfroe drove in four runs, helping the Angels avoid a four-game series sweep.
Ohtani gave up a run in two hitless innings, walking the leadoff hitter and throwing two wild pitches before Rob Refsnyder’s run-scoring groundout.
He’s given up only two runs in 21 innings over four starts this season.
Renfroe, who hit 31 home runs with the Red Sox in 2021, hit a 95.6 mph sinker from Brayan Bello (0-1) into the last row of the Green Monster seats during a four-run first. Brandon Drury added a sacrifice fly in the inning.
Rafael Devers’ RBI single off Carlos Estévez sliced the score to 5-4 in the ninth. But Estévez struck out Refsnyder and got Masataka Yoshida to pop out with two runners on for the final out and his second save.
Unlike most years when the Boston Marathon’s lead runners go through nearby Kenmore Square while the game’s going on, men’s defending champion Evans Chebet crossed the finish line about 25 minutes before the first pitch.
Heavy rain fell briefly before Ohtani took the mound in the second inning and the grounds crew spread a rapid drying agent around the infield, causing a brief delay.
(Michael Dwyer / Associated Press)
The second “official” delay came in the top of the third after the start was pushed back 56 minutes by rain, and that was it on the mound for Ohtani.
He struck out three, throwing 31 pitches, 20 strikes, but went 2 for 5 at the plate with two singles.
Tucker Davidson (1-1) worked 3 1/3 innings for the victory.
Zach Neto, the Angels’ 22-year-old shortstop who was promoted from double-A on Saturday, singled to left for his first major-league hit after starting his career 0 for 9.
Ohtani struck out former World Baseball Classic teammate Yoshida swinging with a 98.4 mph fastball in their only matchup in the first inning.
Bello allowed five runs and eight hits in 2 2/3 innings.