ST. LOUIS (AP) -- Luke Weaver gave the St. Louis Cardinals' ravaged pitching staff a big boost.
Making his third start of the season, the rookie right-hander struck out 10 in seven scoreless innings to help the Cardinals beat the San Diego Padres 6-2 on Wednesday night.
"I felt great," Weaver said. "I felt like everything was rolling really well. The command of the fastball was the biggest thing for me tonight."
The Cardinals had lost three straight and six of eight following an eight-game winning streak, and had allowed at least five runs in each of the last 12 games.
"We needed that," Cardinals manager Mike Matheny said.
Weaver (2-1), who turned 24 on Monday, allowed three hits in his longest career outing and matched his career best with 10 strikeouts.
"He had everything and then he was able to raise the eye level, he was able to make real nice fastball pitches late in the count," Matheny said. "Just an impressive start."
San Diego's Jhoulys Chacin (11-9) allowed five runs -- four earned -- on six hits in 4 2-3 innings. He struck out three, walked three and hit four batters.
"It just wasn't a clean outing from him today," Padres manager Andy Green said. "It was a fight from the beginning."
The Cardinals' leadoff hitters reached and scored in four of the first five innings. Three of those runs scored with two outs.
Second baseman Kolten Wong, batting in the leadoff spot with Matt Carpenter unavailable, sparked the St. Louis offense with three hits, three runs scored and two stolen bases.
The Cardinals opened the first inning with back-to-back doubles, with Tommy Pham driving in Wong, and Pham scoring on Dexter Fowler's sacrifice fly to make it 2-0.
Wong led off the third with a single and scored on Jedd Gyorko's two-out infield single. Greg Garcia scored on Chacin's two-out throwing error on an errant pickoff in the fourth, making it 4-0. Fowler scored on Chacin's bases-loaded wild pitch in the fifth.
Manuel Margot's triple off reliever Seung Hwan Oh in the eighth plated the Padres' first run, making it 5-1. Cory Spangenberg hit a solo home run, his 13th, off John Brebbia in the ninth.
ROSENTHAL TO HAVE TOMMY JOHN SURGERY
Cardinals closer Trevor Rosenthal will have Tommy John surgery. The team announced the decision Wednesday after moving the hard-throwing right-hander from the 10-day disabled list to the 60-day DL.
"I think just the timing of it, being right in the middle of this race and the way my personal season had been taking shape and the way the team has been playing recently. Tough timing," Rosenthal said. "It felt like we were getting in a groove, I was in a groove, and to kind of have this happen and take a piece away from a really good team is a little bit of a bummer."
Rosenthal, who had 93 saves in 2014-15, lost the closer's job a year ago to Oh, but reclaimed it this season after Oh struggled. Rosenthal recorded 11 saves this season, giving him 118 over the past four years.
"We hoped for better news," Matheny said. "Somebody is going to have to step in. He was really throwing the ball well."
HIT BY PITCHES
The Cardinals were hit by pitches five times, the most in team history since 1913.
"You never like it," Matheny said. "A couple breaking balls, too, breaking down the back foot. Fortunately everybody came out relatively unscathed."
Chacin's four hit batsmen set a Padres record and tied the major league mark by John Lackey this season. No pitcher has hit more than four batters in a game since 1903.
"That's really weird for me there, that many batters," Chacin said. "Just my ball was moving crazy."
Padres: RHP Miguel Diaz (strained right forearm) is expected to make one more rehab start in the minors before returning to the majors.
Cardinals: 1B Matt Carpenter missed the game because of illness. Gyorko, starting in place of Carpenter, made his 10th career start at first base.
Padres: RHP Luis Perdormo (6-8, 4.93), a former Cardinals minor leaguer, will make his second career appearance against his former organization Thursday night.
Cardinals: RHP Carlos Martinez (10-9, 3.57) is 1-0 with a 1.98 ERA in two career starts against the Padres at Busch Stadium.