BOSTON — The Yankees are starting to look like Secretariat in the Belmont Stakes.
Even on a night when Nestor Cortes came up with his roughest start of the season, the Yankees used their offense and bullpen to further cement their place as the best team in the division — as well as in the majors — with a 12-5 win over the Red Sox.
In front of a raucous sellout crowd at Fenway Park, the Yankees got a three-run homer from Josh Donaldson — who has homered in three straight games — and enough from their bullpen to send Boston to its fourth consecutive loss.
And they’ve built a season-high 15 ½-game lead in the AL East with their 61-23 start, thanks in part to a 28-12 record in the division.
Cortes lasted a season-low 3 ²/₃ innings, while allowing four runs on eight hits to push his ERA up to 2.74.
But the Yankees hardly felt it, as they got to Boston right-hander Connor Seabold quickly.
DJ LeMahieu led off the game with a single and moved to second on a rocket grounder to third by Aaron Judge that was snared by a diving Rafael Devers.
Matt Carpenter was hit by a pitch and Gleyber Torres followed with a run-scoring single.
Donaldson, who hit a grand slam in Thursday’s win, then delivered a three-run shot to left to give the Yankees a 4-0 lead.
Seabold survived the inning, but needed 37 pitches to do so.
Cortes was shaky in the bottom of the first.
Boston had two on and two out thanks to singles by former Yankee Rob Refsnyder and J.D. Martinez when Christian Vazquez hit a two-run double to left-center, cutting the Yankees’ lead to 4-2.
An RBI double by Carpenter drove home LeMahieu in the second.
The Yankees added to their lead in the third — with some help from Christian Arroyo in right field.
Aaron Hicks walked and Jose Trevino doubled before Marwin Gonzalez popped out for the first out, bringing up the struggling Joey Gallo.
Gallo lofted a fly ball to right, but Arroyo lost the ball in the dusk or the lights and ended up nowhere near where it landed. That allowed Hicks and Trevino to score, but Gallo was thrown out at the plate trying for an inside-the-park homer after an ill-advised send from third base coach Luis Rojas.
Seabold left with right forearm tightness and the Yankees continued to pour it on in the fourth against reliever Michael Feliz.
Carpenter led off with a homer, his ninth of the season. Donaldson and Hicks executed a double steal later in the inning, with Donaldson scoring on a throwing error by Vazquez from behind the plate.
But Cortes’ struggles continued in the bottom of the fourth. Trevor Story and Bobby Dalbec hit homers and the left-hander was pulled with two on and two out.
Miguel Castro came on to face Xander Bogaerts and hit him with a 2-2 pitch to load the bases for Vazquez. Castro got to a full count against Vazquez before striking him out to end the inning.
Albert Abreu, who had not been scored upon in five appearances since rejoining the Yankees last month, gave up a run in the sixth and left with runners on the corners and two outs.
Lucas Luetge entered to face Alex Verdugo and walked him to load the bases. Facing Story, Luetge got the second baseman to pop to second and subsequently tossed 3 ¹/₃ scoreless innings to finish the game.
The Red Sox were further embarrassed by putting Jackie Bradley Jr. on the mound in the ninth. He walked Isiah Kiner-Falefa with the bases loaded to force in a run.
