After only three pitches in his Double-A debut, Boston Red Sox promising pitching prospect Bryan Mata gave up two singles.

So, what was all the hype about?

This: Mata allowed only three more hits the rest of his outing as he shut down the Trenton Thunder in a 7-1 victory Tuesday evening in the first game of a doubleheader at Hadlock Field.

The Sea Dogs made it a sweep with a 1-0 win in Game 2 despite getting only one hit.

Mata, only 20, utilized a 98 mph fastball and plenty of secondary support to last six innings (86 pitches). Besides giving up five hits, he allowed one run and two walks, striking out five.

“I was extremely impressed,” said Sea Dogs pitching coach Paul Abbott, who watched Mata for the first time.

“He was composed. Saved himself. Used all his pitches. Good fastball. Good cutter. Kept them off balance and mixed it up pretty good.”

Mata gave up a leadoff single. Then Kyle Holder placed a perfect bunt toward the second baseman for runners on first and second. Mata yielded a one-out walk to load the bases and an RBI fielder’s choice.

Portland got that back and more with five unearned runs in the first, knocking out Trenton starter Albert Abreu (4-7), considered the Yankees’ No. 3 prospect by mlb.com.

With one out C.J. Chatham struck out but reached on a wild pitch. Bobby Dalbec grounded to the third baseman. Instead of starting a double play, Gosuke Katch’s throw sailed into right field. After a strikeout, the next five Sea Dogs reached, including Luke Tendler’s three-run double.

The support was plenty for Mata. His electric fastball was balanced with a curveball (80 mph) that was good for two called third strikes, a change-up (86) and a new cut fastball (89-90) that has added to his arsenal. He retired eight straight at one point before yielding singles in the fifth and sixth innings.

“I set the tone with my fastball and my secondary pitches were really good, too,” Mata said through an interpreter.

Mata, from Venezuela, was a bargain signing 3 1/2 years ago at $25,000. He developed quickly and leapfrogged two levels of development to start for low Class A Greenville in 2017. Mata showed promise, but injuries slowed his progress, including back spasms that limited him to 50 innings last year.

He looked on track this season in advanced Class A Salem until he was shelved for a month with a shoulder strain. He came back June 7 and showed enough in four starts (1.23 ERA, 21 strikeouts in 22 innings) to earn a ticket to Portland.

“I’m 100 percent healthy, really ready to go,” Mata said.

In the second game, catcher Charlie Madden got Portland’s only hit, an RBI single in the second inning (after two walks). Daniel McGrath (2-0) pitched five innings of two-hit ball, and Dedgar Jimenez pitched two hitless innings for his first save, in his new bullpen role. Trenton’s Nick Nelson (2-2) was the hard-luck loser, despite striking out 11.

NOTES: Chatham injured his knee while hustling to make a catch in left field in the sixth inning of the first game. Chatham left the game. The extent of the injury was not known. Chatham went 2 for 3 in the game, boosting his team-leading average to .322 … Sea Dogs Manager Joe Oliver fell ill during the first game and left Hadlock for home … To make room for Mata in the rotation, Jimenez was moved to the bullpen … A former Sea Dogs starter, Darwinzon Hernandez, was moved to the Triple-A Pawtucket bullpen, with hopes of eventually helping Boston this year, Red Sox President Dave Dombrowski told reporters in Toronto on Tuesday … Dombrowski was asked about Sea Dogs starter Tanner Houck’s possible role with Boston this year. “Houck’s situation is still to be determined,” Dombrowski told masslive.com. “But we do think he’s somebody that could help us in the bullpen, too.”