Yainer Diaz’s tiebreaking solo homer with one out in the ninth inning lifted the Houston Astros to a 5-4 win over the Boston Red Sox on Monday night.

The Astros tied it on an RBI single by Mauricio Dubón in the eighth inning. Red Sox closer Kenley Jansen (3-2) struck out Yordan Alvarez on three pitches in the ninth before Diaz, who also homered Sunday, sent the next pitch deep to left-center field to give Houston its 11th victory in 12 games.

Josh Hader (6-6) pitched a scoreless ninth for the win.

The Astros won despite committing a season-high four errors on an uncharacteristically sloppy defensive night.

Jarren Duran hit a leadoff home run and Masataka Yoshida’s two-run homer in the sixth put the Red Sox up 4-2.

Red Sox starter Tanner Houck allowed eight hits and three runs — two earned — with eight strikeouts in six innings.

Houston starter Yusei Kikuchi gave up six hits and three runs — one earned — in 5 2/3 innings in his fourth start since a July 29th trade from Toronto.

The score was tied at 2-all when Romy Gonzalez reached to start the sixth on a throwing error by Jose Altuve. He was still on first with two outs when Kikuchi was lifted for Tayler Scott. Yoshida connected on his third pitch, smacking it off the railing on the wall in left field to give the Red Sox the 4-2 lead.

Jeremy Peña singled with no outs in the sixth and moved to third on a single by Victor Caratini. The Astros cut the lead to 4-3 when Peña scored on a sacrifice fly by pinch-hitter Jon Singleton with one out.

Duran sent Kikuchi’s first pitch into the Crawford Boxes in left field to put the Red Sox up early. Rob Refsnyder and Rafael Devers hit back-to-back singles with one out in the first.

Gonzalez then reached on a fielder’s choice and Refsnyder was tagged out at home. The Red Sox made it 2-0 when Danny Jansen reached and Devers scored on an error by rookie third baseman Shay Whitcomb.

Alvarez doubled with no outs in the fourth before a single by Diaz. Alvarez was first called safe when he slid home on a ball hit by Peña. But the Red Sox challenged the call and it was overturned.

Caratini then singled on a grounder to right field to score Diaz and Peña and tie it at 2-all.

TRAINER’S ROOM

Astros: RHP Justin Verlander will come off the injured list to start Wednesday’s finale. The 41-year-old ace hasn’t pitched since June 9 because of stiffness in his neck. He made two minor league rehabilitation starts, last throwing four innings for Double-A Corpus Christi on Thursday.

UP NEXT

Red Sox RHP Nick Pivetta (5-8, 4.49 ERA) opposes Astros RHP Ronel Blanco (9-6, 2.89) when the series continues Tuesday night.