SAN DIEGO -- Manager Joe Maddon sounded a bit frustrated Monday afternoon after his Chicago Cubs stranded seven runners in scoring position in a 5-2 loss to the San Diego Padres at Petco Park.

"We had 11 left on base in this game and only three hits, that's the real tale of the tape," Maddon said after a fourth-inning grand slam by rookie Hunter Renfroe off Kyle Hendricks helped hand the Cubs a fourth straight loss for the third time this season, dropping the reigning World Series champions to 25-25.

"That's the story more so than Kyle's performance. We just have to be more efficient. That's the thing that has to happen for us. We need to hit like we're capable of hitting."

Five Padres pitchers combined to hold the Cubs to three hits. However, San Diego pitchers also walked 10 Cubs and hit two.

Twice the Cubs left the bases loaded. Four times they failed to get a runner home from scoring position with less than two outs. Once they didn't score with a runner at third and no one out.

"We've tried everything possible," Maddon said. "Guys have been rested. We've given guys days off. These are our players. I have all the faith in the world.

"We came off a 7-2 homestand. Everybody loved us a couple days ago. And now, all of a sudden, we've had a rough time scoring runs on the road, and we just got to do better. That's all it comes down to.

"The thing is everyone's trying too hard, proverbially, way too hard ... just try not to hit homers, but really just take what they give you. Play with the middle. You've got to convince them to do it. It's not that complicated.

"You can see big swings coming out of our zone when just a single would do. We've done it before. We can do it again."

But the Cubs didn't do it Monday. They were 1-for-10 with runners in scoring position. The lone hit was Jason Heyward's two-out, two-run, bases-loaded single that followed two walks and a hit batter from Padres starter Jarred Cosart in the first to give Chicago a quick 2-0 lead.

After that, nothing.

Not that it seemed that the Cubs would need a lot the way Hendricks was dealing at the start of the game. He retired the first 10 Padres he faced, including five by strikeout. But the game turned instantly on Hendricks, who entered with a career 1.56 ERA against the Padres.

Yangervis Solarte started the San Diego fourth-inning rally with a one-out single on a grounder toward center. The ball was stopped on the outfield grass by Cubs second baseman Javier Baez, whose throw to first was just late.

Wil Myers followed with a single to right, and Hendricks hit Ryan Schimpf with a pitch to load the bases.

Renfroe unloaded them on a 1-1 sinker from Hendricks, his 374-foot drive to left being the 10th homer of his rookie season and the second grand slam of his career.

"He threw me the same pitch on my first at-bat and I was late on it," Renfroe said. "I thought he'd come back to it."

Hendricks said, "I was just trying to run a fastball in there that kind of straightened out on me. That's how it goes."

The Padres extended their lead to 5-2 in the fifth on three consecutive singles by reliever Jose Torres (his first major league hit), Allen Cordoba and Solarte and a groundout by Myers, who just beat Baez's relay throw on a potential inning-ending double play.

Hendricks (4-3) departed after five innings. He gave up five runs on six hits and a hit batter with no walks and five strikeouts. Seven of the last 11 hitters he faced reached base.

Meanwhile, Cosart was gone before Hendricks. After lasting only 2 2/3 innings in his previous start, Cosart went four innings Monday, with only 42 of his 87 pitches going for strikes. He allowed two runs on three hits and five walks while striking out two.

While Padres manager Andy Green was happy with a second straight win, he wasn't exactly delighted with the process.

"That should have been a disaster pitching-wise," said Green. "Ten walks and two hit batters is not a recipe for success. We're very fortunate."

Speaking of Cosart, Green said: "You don't stay in the major leagues like that."

Torres (3-2) got credit for the win with two scoreless innings in relief of Cosart. Brandon Maurer got his second save in as many days and his seventh of the season.

NOTES: Before Monday's game, the Cubs recalled RHP Justin Grimm from Triple-A Iowa and optioned RHP Felix Pena to Iowa. Grimm, 28, started his third stint with the Cubs by allowing a hit with two strikeouts in two scoreless innings Monday. ... SS Chase d'Arnaud made two more defensive gems in his second straight start for the Padres. ... Padres 2B Yangervis Solarte and Cubs OF Jason Heyward were the only players to collect two hits. ... RF Ben Zobrist, Chicago's leadoff hitter, drew three walks while going 0-for-1.