Kansas City Royals relief pitcher Aaron Crow walks back to the mound after giving up a two-run single to St. Louis Cardinals' Daniel Descalso during the eighth inning of a baseball game Wednesday, May 29, 2013, in St. Louis. The Cardinals won 5-3. (AP Photo/Jeff Roberson)The Associated Press
Kansas City Royals starting pitcher Luis Mendoza reacts after driving in a run with his first career hit, a single, in the fifth inning against the St. Louis Cardinals in a baseball game Wednesday, May 29, 2013, in St. Louis. The Cardinals won 5-3. (AP Photo/St. Louis Post-Dispatch, Chris Lee) EDWARDSVILLE OUT ALTON OUTThe Associated Press
St. Louis Cardinals' Daniel Descalso, right, applauds as he stands on second near Kansas City Royals shortstop Alcides Escobar after hitting a two-run single during the eighth inning of a baseball game Wednesday, May 29, 2013, in St. Louis. Descalso went on to second on the throw. The Cardinals won 5-3. (AP Photo/Jeff Roberson)The Associated Press
St. Louis Cardinals' Allen Craig, right, scores ahead of the tag from Kansas City Royals catcher George Kottaras during the eighth inning of a baseball game Wednesday, May 29, 2013, in St. Louis. The Cardinals won 5-3. (AP Photo/Jeff Roberson)The Associated Press
ST. LOUIS – For the third straight start, Luis Mendoza left with the Kansas City Royals leading. He made a big contribution at the plate, too, with his first career hit and RBI.
Mendoza has three no-decisions to show for it after the St. Louis Cardinals victimized setup man Aaron Crow in a four-run eighth of a 5-3 victory on Wednesday.
Crow, the Royals' first-round pick in 2009 out of Missouri, readily accepted the blame and called it "the worst I've ever pitched in my career by far."
"Leaving the ball up, giving them good pitches to hit. In that situation, that's not going to get the job done," Crow said. "I feel like I let everyone in this clubhouse down tonight."
The Cardinals had been 0-12 when trailing after seven innings before getting four runs on five hits off Crow in a rally that began with Carlos Beltran's leadoff home run.
"That was a real bad pitch," Crow said. "He's a great hitter and there's a lot of guys who are going to hit that pitch. You can't make a mistake to a hitter as good as he is. He hammered it."
Pinch-hitter Daniel Descalso hit a two-run single with the bases loaded to snap a tie in the eighth for the Cardinals.
"Aaron just didn't have it," manager Ned Yost said. "One of those nights where there wasn't much quality in terms of pitch location, too many hittable pitches behind in the count. Paid the price."
Mendoza allowed a run in 5 2-3 innings before the bullpen failed and the Royals lost their season-worst eighth in a row. They dropped the first two games of the interleague series by a combined 10-4 score and have totaled 11 runs the last six games.
"When your pitcher gets an RBI single, you have to be feeling good," Yost said. "One of those games we're going to break through, good things are happening."
Matt Holliday and Beltran both homered for the second straight day for the Cardinals, who have won seven of eight and lead the majors with a 35-17 record. They go for a sweep Thursday with touted rookie Michael Wacha making his major league debut.
Randy Choate (1-0) got the last out in the eighth and Edward Mujica finished for his 17th save in 17 chances
Lance Lynn missed a chance to go 8-1 the first two months both of his seasons in the St. Louis rotation, allowing two runs in seven innings.
After Beltran hit his 12th homer, David Freese tied it with a one-out RBI single. Crow intentionally walked Jon Jay to load the bases, then got Pete Kozma on a called third strike before Descalso bounced one up the middle for his first pinch-hit RBIs of the season.
Royals rookie David Lough had two hits for a two-game total of six and threw out a runner at the plate. Alex Gordon had three hits and Lorenzo Cain and George Kottaras had an RBI apiece.
The Busch Stadium field showed little signs of wear six days after the mound was removed and the infield dirt covered with sod for an exhibition soccer match between English Premier League rivals Chelsea and Manchester City that drew a standing room crowd.
Mendoza retired the side in order in the first, a welcome change for the Royals after Molina and Beltran opened with two-run homers the first two games.
The Royals traveled Interstate 70 by bus for the second half of the interleague series after difficulties with the team flight.
Notes: Mike Moustakas returned for the Royals after missing three games with quad tightness and had two hits. ... Gordon is batting .404 on the road and is among the leaders with 23 multihit games. ... Beltran saved a run in the seventh with a sliding catch on a drive near the RF line by Cain. ... Cardinals 2B Matt Carpenter made an outstanding play in the second, diving to his right to snare a liner by Chris Getz, the only hard-hit ball from the Royals the first time through the order.