PITTSBURGH — Jonathon Niese’s winning streak ended, so the Pittsburgh Pirates’ losing streak didn’t.

Niese was tagged for season highs in hits and runs, and the Pirates lost their fifth in a row when the St. Louis Cardinals finished off a three-game sweep with an 8-3 victory Sunday.

“I thought this was one of the better days I’ve felt pitching, but that’s how this game goes sometimes,” said Niese, who won his previous three decisions and hadn’t lost since May 9. “Sometimes, you don’t feel great and you have a great game; sometimes, you feel great and don’t have a good game. It’s just one of those days.

“Some breaks didn’t go my way. When I needed to execute a pitch, I made a mistake,” he added.

Prominent among Niese’s mistakes were solo home runs allowed to Matt Holliday and Randal Grichuk. Holliday and Yadier Molina each had three hits for the Cardinals, who have won five consecutive games and completed a sweep at PNC Park for the first time since August 2009.

“We just tried to come here and play the game the right way and tried to win games, and obviously we haven’t done this in a long time here, a sweep,” Molina said. “This is great; we played a great three games.”

Molina and Holliday have combined for 310 career hits against Pittsburgh. Mike Leake, who tossed seven effective innings, had won seven straight decisions versus the Pirates before losing his previous outing against them in April.

St. Louis entered the weekend having lost 22 of its past 31 in Pittsburgh, but won a series at PNC Park for the first time since 2012.

Leake (5-4) won for the fifth time in six decisions, limiting the Pirates to two earned runs and six singles with no walks and six strikeouts. He also went 2 for 3 at the plate and scored during the Cardinals’ three-run third.

“My fastball-cutter combination was working pretty well,” Leake said.

The slumping Pirates are on their longest losing streak of the season. They fell a season-high 12 games behind the first-place Cubs in the NL Central.

St. Louis scored four times in the sixth, capped by Grichuk’s solo homer to left field that ended the evening for Niese (6-3). Grichuk snapped out of a 2-for-24 slump with the home run, his eighth.

Niese was charged with eight runs and 11 hits in 5 1/3 innings.

“A couple innings there snowballed on me,” Niese said. “And that was the difference.”

The left-hander was 3-1 with a 1.74 ERA over his past five starts and tossed seven scoreless innings in his previous outing.

“He was in the zone,” Pittsburgh manager Clint Hurdle said, “but a lot of those times the execution was lacking. A lot of balls got up a little bit, more so than normal.”

David Freese and Starling Marte each had two hits and an RBI for the Pirates.

TRAINER’S ROOM

Hurdle said the team was still awaiting test results before determining whether RHP Gerrit Cole will pitch Thursday. Cole left his start last Friday because of right triceps tightness. ... After leaving Saturday’s game when he aggravated a foot injury, catcher Chris Stewart did not start Sunday but was available off the bench.

UP NEXT

For the first time in 32 days, the Pirates have a scheduled off day Monday. They will travel to New York to face the Mets from Tuesday through Thursday after taking two of three from the defending NL champions at PNC Park last week. Tuesday’s pitching matchup is Pittsburgh RHP Juan Nicasio (5-5, 5.34 ERA) vs. New York RHP Jacob deGrom (3-2, 2.80).