Boston Red Sox closer Aroldis Chapman, who at 37 is as dominant as he has been in his career, added to his “special” season by striking out four batters in an inning Sunday.

The eight-time All-Star, who signed a $13.3 million contract for 2026 last week, is enjoying one of the most dominating runs by a relief pitcher in baseball history.

Locating his off-speed pitches with the 100-plus mph fastball, Chapman has gone 17 straight appearances — spanning 14⅔ innings — without allowing a hit, dating to July 26. It’s the third-longest streak since 1901, trailing only the 20 straight by the Marlins’ Randy Choate in 2011 and 18 consecutive by Tim Byrdak of the New York Mets in 2012.

“This is special,” said Boston manager Alex Cora, who earned his 600th career win with Sunday’s 7-4 win over the Arizona Diamondbacks. “To do it at this age and where we’re at as an industry, as far as the hitters and the adjustments they make, it’s unreal.”

Chapman has allowed one earned run in his past 37 games — a solo homer by Philadelphia Phillies’ J.T. Realmuto on July 23 — and retired 21 straight batters before Arizona’s Ildemaro Vargas reached first after striking out on a wild pitch Sunday.

Chapman then closed out his 29th save by striking out Jordan Lawlar to become the second pitcher to record four K’s in an inning this season, joining St. Louis Cardinals’ Steven Matz, who did it in June. Chapman has allowed six earned runs all season and dropped his ERA to 0.98 with Sunday’s performance.

“He’s so nasty, and showing people he can still do a lot of great things,” Red Sox starter Brayan Bello said.

Chapman built his reputation as a power pitcher through 16 years of routinely popping 100 mph on the radar gun. He has clocked eight of the nine fastest pitches in baseball history, including 105.1 mph last season, and his 105.8 mph pitch during his 2010 rookie season is still the fastest in MLB history.

On top of that, however, he has added craftiness to that power, baffling hitters by locating sliders and splitters.

“It’s just something that happened,” Chapman said through an interpreter. “My mentality is to go get three outs and go for a strikeout.”

The Associated Press contributed to this report.