ST. LOUIS -- The Cardinals left Jeff Samardzija stunned on Saturday as they powered their way back from a four-run deficit to steal a series-evening 7-4 victory over the Giants at Busch Stadium.
Samardzija cruised through the first four innings, during which his offense built a lead against Cardinals starter Michael Wacha by tallying a run in four of the five innings Wacha finished. Brandon Moss jolted the Cardinals' offense with a homer to open the fifth. After a pair of two-out hits, including the Cardinals' 33rd pinch-hit of the season, Aledmys Diaz blasted a game-tying three-run homer off the left-field foul pole.
Back-to-back homers by Stephen Piscotty and Matt Adams to open the sixth gave the Cardinals their first lead of the night. The four homers came within a nine-batter span against Samardzija, who had allowed five in 76 innings coming into the start. Adams' homer ended Samardzija's night.
"We're down, 4-0, and the other guy is dealing -- and he had good, good stuff today -- but you just sense if we get a couple guys on base, something good can happen here," said Cardinals manager Mike Matheny. "And that's a good place to have your offense."
"Those guys score a lot of runs and they have some power," Giants shortstop Brandon Crawford said of the Cardinals, who lead the National League in scoring and were tied with the Mets for the league lead in homers. "You're going to have games like that. It did happen pretty fast, though."
Saturday marked the Cardinals' fifth four-homer game this season, more than the club had in its past three seasons combined. The Cardinals have now connected for back-to-back blasts on four different occasions.
• Homers becoming part of Cards' forte
"The old saying 'Hitting is contagious' absolutely holds true," Piscotty said. "Moss got it rolling for us. We needed something to kind of break the rhythm that Samardzija was in."
MOMENTS THAT MATTERED
Diaz's dinger: Diaz drew a curtain call after snapping an 0-for-9 skid with his fifth-inning blast. He took Samardzija deep on a 3-0 fastball, which, according to Statcast™, landed 426 feet away and came off the rookie shortstop's bat at 107 mph. The home run, which ensured that Wacha would not take a seventh consecutive loss, came on the first swing Diaz has had on a 3-0 pitch this season.

"I knew we [were facing] a great pitcher today who was throwing 97-98 [mph]," Diaz said. "I just looked for the fastball, and luckily he threw the fastball." More >
Bad flashback: The Giants knew nothing of the Samardzija who allowed 29 home runs last year for the White Sox, which tied him for the American League lead in that dubious category. However, that version of Samardzija was very much in evidence as he matched a career worst by yielding four homers. He also allowed four to the Angels on July 10, 2013.

"I don't think anything was out of the ordinary," Samardzija said. "Unfortunately, I got into a situation where they got a couple of pitches up, especially that 3-0 one [to Diaz], and they took advantage of it." More >
Feeling Rosey: A few hours after giving Trevor Rosenthal his vote of confidence, manager Mike Matheny, as promised, summoned the right-hander in to lock down the three-run victory. Rosenthal retired the side in order on 11 pitches. Rosenthal, who has now converted nine of his 10 save opportunities, walked all three batters he faced one night earlier. This represented just the second time all season that Rosenthal had pitched on back-to-back days.

"Not a whole lot felt different," Rosenthal said. "I'm still working, trying to get in that groove and find a good rhythm. I think today is a good starting point, for sure, as far as results go." More >
By any means necessary: The Giants looked aggressive on the basepaths. Crawford doubled and tripled, running hard to take one extra base on each occasion. Joe Panik was thrown out in the first inning as he tried to stretch his RBI double into a triple, but it wasn't an egregious baserunning mistake.

With right fielder Hunter Pence likely to be sidelined for eight weeks after upcoming hamstring surgery, the Giants might need to seize every scoring chance they can get.
"Whenever you can get an extra 90 feet, it'll be big for your offense," Crawford said. "Missing a guy that has some power and who can hit the ball out of the park, though, that might be a little bit bigger. Because when you're on second base, a single can score you, instead of being on first, where you might need an extra-base hit. We have some team speed that's going to be able to stretch those in-betweeners into an extra-base hit."
QUOTABLE
"I would assess him as kind of like a hitter who is trying to find his timing. Michael [Wacha] is trying to fight through innings. You see some sailing high. He's bouncing some cutters. He'll find it. And when he does, this guy has above-average stuff and that should turn into above-average results." -- Matheny on Wacha, who has a 5.16 ERA and remains winless since April 23.
WHAT'S NEXT
Giants: This might be a surprise, given his 6.34 ERA, but Jake Peavy is coming off one of the best starts in his career. Peavy, scheduled to start Sunday's series finale at 6:05 p.m. PT, worked seven innings, faced the minimum and allowed one hit in San Francisco's 4-0 victory Tuesday in Atlanta. Only one other time has he lasted seven shutout innings while allowing one hit -- Aug. 30, 2014, against Milwaukee.
Cardinals: The Cardinals will close this brief three-game homestand on Sunday, when Carlos Martinez takes the mound against San Francisco. Martinez struck out eight over eight scoreless innings in his last start. First pitch is scheduled for 7:05 p.m. CT.
Watch every out-of-market regular-season game live on MLB.TV.