Weaver, Nicasio pitch Cardinals past Pirates 4-1

St. Louis Cardinals starting pitcher Luke Weaver throws during the first inning of a baseball game against the Pittsburgh Pirates, Friday, Sept. 8, 2017, in St. Louis. (AP)

ST. LOUIS (AP) — If the St. Louis Cardinals are going to make the playoffs, rookie starter Luke Weaver will be a big reason why.

Weaver pitched shutout ball into the sixth inning and also drove in a run Friday night, helping the Cardinals improve their postseason hopes with a 4-1 win over the Pittsburgh Pirates.

“It’s just real fun to watch him take advantage of an opportunity like this this time of season,” Cardinals manager Mike Matheny said.

The Cardinals have won seven of nine, pulling within four games of the NL Central-leading Cubs. St. Louis is even closer in the chase for the second wild-card spot.

The Pirates have lost three in a row.

Weaver (5-1) has won five straight decisions and his last four starts, not allowing more than two runs in any of them. He gave up seven hits, walked none and struck out seven in 5 2/3 innings.

“I thought it was good,” Weaver said. “I was getting a little more movement on the fastball than usual, so the ball was kind of leaking out over the plate a little bit. Gave up a few hits on just fastballs that weren’t commanded very well but just rebounded well. Got some groundballs, some double plays and that was big and just tried to manage it the best I could.”

Weaver drove in the Cardinals’ first run with a broken-bat groundout and scored a run.

Juan Nicasio made his St. Louis debut and got four outs for his third save. The Cardinals got him from Philadelphia for a minor leaguer earlier in the week.

Nicasio pitched most of the season with Pittsburgh before being plucked off waivers by the Phillies in late August. He spent just six days with the Phillies, appearing in two games.

“I’m really happy to be part of this organization,” Nicasio said through a translator. “Even more to be part of this postseason run.”

Trevor Williams (6-8) allowed four runs in 4 2/3 innings.

The Cardinals returned home in the early-morning hours after going 7-3 on a road trip that finished in San Diego. The Pirates began a nine-game swing after going 4-3 at home to start September.

Williams gave up runs in the third and fourth, and a two-run single in the fifth to Jose Martinez.

“The pitch to Martinez is the one that hurt,” Pittsburgh manager Clint Hurdle said. “Two strikes, elevated fastball. (Williams) wasn’t able to make pitches later on in some situations he got himself into. The fifth inning hurt.”

Pinch-hitter Adam Frazier singled in the seventh for Pittsburgh’s run.

TAKING A BREAK

Cardinals rookie INF Paul DeJong didn’t start for the first time since July 6. He was coming off an 8-for-42 (.190) road trip. DeJong is hitting .284 with 21 home runs and 55 RBIs.

TRAINER’S ROOM

Cardinals: 2B Kolten Wong (sore back) is expected to be back in the lineup Saturday night. Manager Mike Matheny said he thought Wong would be available to pinch hit. … 3B Matt Carpenter (right shoulder strain) returned to the lineup and hit leadoff.

Pirates: OF Gregory Polanco and Frazier were both reinstated from the disabled list for Friday’s game. Polanco batted third and played right field.

UP NEXT Cardinals: RHP Carlos Martinez (11-10, 3.34) faces the Pirates on Saturday. He is 5-5 with a 3.53 ERA in 11 career starts vs. Pittsburgh. Martinez established a new single-season high with 192 strikeouts in his previous start.

Pirates: RHP Chad Kuhl (7-10, 4.32) will make his fourth start of the season vs. St. Louis. Kuhl is 1-1 with a 3.94 ERA against the Cardinals. Kuhl has allowed more than two earned runs just four times in his last 18 starts.