Another left-handed starter, another loss for the Chicago Cubs.

It's the same old frustrating story on the North Side.

After the bullpen let the game slip away, the Cubs failed to capitalize on a ninth-inning rally and fell to the Boston Red Sox 7-4 on Sunday night.

The Cubs strung together three straight singles to lead off the ninth inning against Boston closer Alfredo Aceves, but plated only one run as they fell to 7-24 over their last 31 games. The Cubs are 3-15 against left-handed starters this season, by far the worst in the majors.

"You can't even try to do what we do against left-handed pitching," Cubs manager Dale Sveum said. "It's very difficult to have those kind of numbers against left-handed pitching on a consistent basis."

Franklin Morales, starting in place of the injured Josh Beckett (right shoulder inflammation), gave up two runs and four hits with a career-high nine strikeouts in five innings. It was his first start of the year and 16th of his career.

Trailing 3-2, the Cubs capitalized on several defensive miscues by the Red Sox to tie the game in the sixth, but gave it back, and then some, in the seventh.

Shawn Camp (2-4) gave up hits to both batters he faced — a double to Darnell McDonald and single to Jarrod Saltalamacchia — to start the seventh.

Ryan Kalish then singled to center off James Russell to drive in McDonald and put the Red Sox ahead 4-3. Saltalamacchia scored on pinch-hitter Will Middlebrooks' sacrifice fly, with Kalish advancing to third on catcher Wellington Castillo's fielding error. Kalish then scored on Daniel Nava's squeeze bunt.

Kalish was called up from Triple-A Pawtucket before the game and inserted into the starting lineup as the Red Sox placed outfielder Ryan Sweeney on the 15-day disabled list with irritation in a bone on his left foot.

"Got a chance in a big situation, kind of got over-anxious at first," said Kalish, whose last Major League at-bat was October 3, 2010. "I just stepped out, told myself This is baseball, I've been here before.'"

Nava entered the game in the sixth inning in place of Scott Podsednik, who left with left groin discomfort. The Red Sox currently have 12 players on the disabled list.

Matt Albers (2-0) pitched one inning to pick up the win.

David Ortiz hit his 16th home run of the season in the fourth inning when he drove a 2-2 changeup off Cubs starter Paul Maholm to the left-center field bleachers, giving Boston a 3-2 lead.

Maholm was tagged for two runs in the first when Dustin Pedroia doubled home Podsednik, later scoring on a single by Ortiz. He was charged with three runs over six innings of work.

"They're a good lineup, from top to bottom," Maholm said. "They try to make you get the ball up so they can do damage. It's more or less sitting back and waiting for you to make a mistake."

Starlin Castro, who had three hits and two RBIs to end a 2-for 21 slide, got the Cubs on the board in the bottom of the first with an RBI triple.

But it was the 2 for 12 with runners in scoring position that stuck out, including the failed ninth-inning rally.

The Cubs loaded the bases with no outs against Aceves in the ninth, but after David DeJesus hit a sacrifice fly to center, Reed Johnson struck out and Darwin Barney hit a popup to third baseman Nick Punto to end the game

"We can't score when it's close, or we can't make a pitch when it's close to hold them or shut them down, or get the game into extra innings," Sveum said. "We have to be better at those things, somebody stepping up and getting a big hit when it counts, not when we're four and five runs down."

NOTES: Sveum said the team will likely activate C Geovany Soto from the 15-day DL on Monday before the series opener against the White Sox. ... C Koyie Hill was released by the Cubs on Sunday after declining an assignment to Triple-A Iowa after clearing waivers. ... Red Sox 1B Adrian Gonzalez was out of the starting lineup for the first time this season. He struck out as a pinch-hitter the ninth. ... RHP Matt Garza (2-5, 4.04 ERA) will pitch Monday for the Cubs. ... The Red Sox are off on Monday and Clay Buchholz (7-2, 5.38) will take the hill on Tuesday at home against the Miami Marlins.