The Cubs pulled within 3-2 in the fourth with some clutch two-out hitting. With one out, Ryan Kalish singled and John Baker walked. After a groundout moved the runners to second and third, Cubs starter Jason Hammel singled to right to drive in both.
Molina's go-ahead single to center came on the sixth pitch of the at-bat from Randon.
"I thought I made a good pitch today, but something happened," Randon said.
Molina seemed more relieved that the wild pitch wasn't a factor than he drove in the game-deciding runs.
"(Molina) does a good job of not wearing his emotions and how frustrating that is for him," Matheny said. "It's hard to count the number of balls he keeps in front of him, the number of runs he saves. It's something we don't take for granted."
Valbuena doubled in a run with two outs in the ninth to make it 5-4, but Rosenthal got Anthony Rizzo to ground out to end the game.
"Guys kept grinding it out," Cubs manager Rick Renteria said. "We just fell a little short."
NOTES: The ESPN broadcast team of Dan Shulman and John Kruk worked from the bleachers. ... While making a rehab start Sunday with Double A Springfield, LHP Jaime Garcia (shoulder) was hit by a pitch on the left elbow and left after two innings and 28 pitches. "I think they went in and took precautionary X-rays," Matheny said. "I haven't heard anything back yet." ... In the same game, RHP Jason Motte threw a scoreless inning, striking out three, in his first rehab outing. ... Rizzo entered with a .429 on-base percentage, which was fifth-best in the National League. ... The Cards open a series in Atlanta on Monday, with RHP Shelby Miller (3-2) facing RHP Aaron Harang, while the Cubs host the crosstown White Sox with RHP Jeff Samardzija (0-3) going up against LHP Jose Quintana (1-2).