What the Pittsburgh Pirates lacked more than pop in the middle of the lineup last season was the synergy to support a strong starting pitching performance.

Braxton Ashcraft got both as he recorded a career-best eight strikeouts without a walk in six innings for a quality start against the Baltimore Orioles on Sunday. The bullpen added six strikeouts, as the Pirates had 14 strikeouts without a walk for only the fourth time in the Modern Era (since 1901).

Ryan O’Hearn continued his red-hot start with his first home run at PNC Park for the Pirates and added a two-run double, Oneil Cruz crushed his fourth homer and the bullpen protected a big lead for an 8-2 win to clinch a three-game series sweep before 11,956 at PNC Park.

“Sweeps in this league are really hard, and I think if you can go out there and kind of give ’em a gut punch early on and go up early, it makes it a lot easier,” O’Hearn said. “So really happy we put some runs on the board early in the game.”

The Pirates (6-3), who won their fifth consecutive game, will welcome the San Diego Padres on Monday for a three-game series. The Padres have won their past six games against the Pirates at PNC Park.

Orioles right-hander Chris Bassitt (0-2), who allowed six runs on six hits and two walks in two innings, was shaky from the start. Bassitt hit Cruz with his third pitch of the game, then got a break when Brandon Lowe hit a line drive directly at first baseman Pete Alonso for an unassisted double play.

But Bassitt walked Bryan Reynolds on four pitches, then threw three balls outside the zone to O’Hearn. When Bassitt left a fastball over the middle of the plate, O’Hearn sent it 402 feet to center field for his third home run of the season to give the Pirates a 2-0 lead.

Ashcraft (1-1), on the other hand, was sharp in drawing 16 called strikes and nine whiffs on his 97 pitches. Ashcraft struck out the side in the second, winning an ABS challenge on a 2-2 curveball to get Dylan Beavers looking to end the frame.

Bassitt’s command issues continued in the second, when he walked leadoff batter Spencer Horwitz on four pitches. Henry Davis followed with a single, and Jake Mangum dropped a bunt toward third and beat Blaze Alexander’s throw for an infield single to load the bases.

Cruz hit a bouncer that ricocheted off the back of Bassitt’s left calf to score Horwitz for a 3-0 lead, but Lowe hit a sharp grounder that Alonso snagged to throw out Davis at home plate. Reynolds hit a sacrifice fly to the warning track in right to score Mangum and make it 4-0. O’Hearn did more damage, smashing a 3-1 sinker to left-center to drive in Cruz and Lowe for a six-run advantage.

“I’m proud of our guys sticking to our approach and staying in the zone and hunting certain pitches, didn’t expand and forced him to come into the zone,” Pirates manager Don Kelly said. “I thought we were really stubborn in our approach, which was really good and stuck to it and did a good job there.”

O’Hearn tied his single-game career best with four RBIs and joined Reb Russell (11, 1922), Ed Stevens (13, 1948), Dick Stuart (11, 1958) and Reggie Sanders (11, 2003) as Pirates with 11 or more RBIs in their first eight games with the team. O’Hearn became the seventh Pirates player to reach base safely multiple times in seven of his first eight games with the club since 1900, joining a list that includes Brian Giles doing so in seven games in 1999.

“It starts with Ryan O’Hearn,” Ashcraft said. “He came in this year and set a precedent. He leads by example in how he plays the game, how he hustles and how he conducts himself day-in and day-out. It’s contagious. We have a lot of good players in this clubhouse. When you show up to work every day and see the people around you putting in the work, it forces you to either run the race with them or fall way behind. I think that everybody is stepping up to that challenge. You see it in the performance and the product we put on the field every day. There’s a lot of good energy floating around this clubhouse right now, and we’re excited for what’s to come.”

Baltimore scored in the fourth after Taylor Ward doubled to right and O’Hearn tried to make a sliding catch but the ball bounced under his glove. Alonso drove Ward in with a double to center to cut it to 6-1.

Orioles left-hander Cade Povich kept the Pirates scoreless for three innings, until Mangum singled to start the sixth and Cruz followed by crushing a 2-2 fastball 415 feet to straightaway center for his National League-leading fourth home run and an 8-1 lead. After struggling against lefties last season — when he went 11 for 108 (.102) with one homer and eight RBIs — Cruz has made a major reversal by going 7 for 11 with three homers and six RBIs.

The Pirates bullpen got three strikeouts in the seventh from lefty Mason Montgomery, who allowed a run on Jeremiah Jackson’s RBI single, and three strikeouts over two scoreless innings from righty Jose Urquidy to finish off the Orioles.

“It’s great when you can win games like that,” Kelly said. “We’ll take a win any way you can get it. (Saturday) was really exciting and same with the home opener. Today, to be able to jump out to a bigger lead and to be able to add on — the starting pitching, bullpen, offense, defense played really well, too. It’s always a lot of fun when you get everything clicking all at once.”