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The Chicago Cubs didn't come to close to ending their longest losing streak in more than 15 years.

Pedro Alvarez, Andrew McCutchen and Garrett Jones homered, Erik Bedard pitched six shutout innings and the Pirates beat Chicago 10-4, sending the Cubs to their 12th consecutive loss.

Pittsburgh used a six-run sixth inning to take a 10-0 lead before the Cubs saved some face by scoring all their runs in the final two innings.

"Not only to not get results, but to feel like you are getting embarrassed, it is frustrating," Cubs catcher Koyie Hill said.

Of the prior 11 losses, six were by one run — including the first two games of this series.

The Cubs managed two hits against Bedard, and Chicago starter Matt Garza (2-3) was tagged for six runs on three home runs in five-plus innings.

"It's upsetting and frustrating, and we need someone to stop this snowballing," Garza said.

"There are no excuses," Garza added. "We are going to turn it around, and we are going to keep plugging away until it turns."

Since McCutchen made his majors debut in June 2009, Pittsburgh has had 18 losing streaks of at least five games. The Pirates lost 12 consecutive in 2010 during their 105-loss season.

"We've been there before, we know how it feels, so we knew if we were able to get on the board early, we pretty much would have them," McCutchen said. "Just because we've been there. When you're (struggling), and then you're down early, it kind of knocks the breath out of you."

Alvarez hit a three-run homer in the first, Pittsburgh's first this season with more than one man on. McCutchen added a solo shot in the fifth and Jones went deep to right with Neil Walker on in the sixth.

Pittsburgh added four more runs against Rafael Dolis and Michael Bowden that inning.

Starlin Castro homered during a three-run eighth for Chicago, which had scored during two of the previous 33 innings.

"We didn't score, again, off the starter, so that magnifies everything," Cubs manager Dale Sveum said. "We didn't muster up really anything today."

Pittsburgh completed its first three-game sweep at PNC Park since Sept. 17-19, 2010.

The lowest-scoring team in baseball, the Pirates set a season high for runs and matched a season high by winning their third consecutive game. The Pirates scored at least 10 runs in a game for the first time since July 3, 2011.

"I was well aware of the fact we didn't have (a three-run homer)," Pittsburgh manager Clint Hurdle said. "They make the offensive game pick up dramatically when you can get three runs in one swipe. About time for us to get one of those."

Bedard (3-5) allowed two hits. He had four walks and three strikeouts.

"To get on a roll like that and score 10 runs, it's nice," said Bedard, who has four losses this season when he allowed two earned runs or less. "It makes it easier for a pitcher to pitch."

After allowing five runs over a stretch of four starts, Garza has been tagged for a total of 13 over eight innings in his past two outings. He was charged with six runs (five earned) on seven hits, a walk and six strikeouts Sunday.

"It's frustrating; the last couple have been frustrating," Garza said. "I need to keep going and going hard. It's going to turn — and it's got to turn.

NOTES: The Cubs completed an 0-6 road trip during which they were not out-hit in a game until Sunday. ... Pirates OF Jose Tabata was 2 for 3 before being removed from the game in the sixth inning due to discomfort and cramping in his left leg. He was to be further evaluated later Sunday and Monday. ... Sveum said that either RHP Shawn Camp or LHP Jeff Russell would work in closing situations. Dolis has been scored on in each of his past five outings. ... Chicago returns home for a three-game series against San Diego in a matchup of the NL's two worst teams. ... Pittsburgh continues a nine-game stretch in which it is 4-2 when it faces NL Central-leading Cincinnati on Monday. The Reds start former Pirates player Bronson Arroyo (2-2, 3.22) in the series opener.