NEW YORK -- Soon after the Mets' first-half finale started, Jon Niese dug himself into an insurmountable hole.
The left-hander had turned into one of the team's most dependable pitchers over the last month. On Sunday, he had a hiccup, as the Mets dropped the finale of their three-game series with the Cubs, 7-0, and moved to 2-4 on the season against Chicago, which entered Sunday's contest tied for the worst record in the Major Leagues.
After giving up just four runs -- three by home run -- in 21 1/3 innings over his last three starts, Niese ran into an unfamiliar bout of trouble in the first frame.
"I felt like I made a lot of good pitches, and then when I had guys in scoring position, I made mistakes and they punished me," Niese said.
That one inning was all it took for Chicago, which nearly batted around in the first to score four runs. Reed Johnson and Starlin Castro led off the game with back-to-back singles, and after Niese got hot-hitting first baseman Anthony Rizzo to fly out, Alfonso Soriano, Jeff Baker and Geovany Soto scattered three more hits to punish the lefty for the most runs he has allowed in a first inning since Sept. 22, 2010.
"Obviously, he was way too much on the plate, too many balls on the middle of the plate," manager Terry Collins said. "He came out trying to get ahead, and they're hammering him on the first pitch. As he showed you after the first inning, he settled down and started making pitches and sailed along."
Niese cruised once he reached the bottom third of Chicago's order and retired 18 of the next 19 batters he faced. Luis Valbuena and Johnson ruined Niese's streak with their seventh-inning singles before Castro put the Cubs up 7-0 by depositing a ball into the seats in left for his first extra-base hit since June 20.
"That three-run homer made it a lot easier for a lot of us," Cubs manager Dale Sveum said.
Collins allowed Niese to finish the seventh inning, but the damage was done. The seven earned runs are the most Niese has allowed since May 18, when he allowed eight over three innings in a rough start in Toronto. While Niese eventually found control of the strike zone on Sunday, Chicago's predominately right-handed lineup hit him hard, as the left-hander allowed a season-high nine hits.
"They were aggressive early. One thing Niese does is he pounds the zone. They were trying to take advantage of a lot of strikes," Mets second baseman Daniel Murphy said. "They put the four on us, and kind of put us behind the eight ball a little bit. It made each opportunity that much more vital."
After scoring 10 runs in the first two games of the series, the Mets couldn't get anything going against Ryan Dempster, who outdueled Niese in his return from the disabled list. Scott Hairston did triple with one out in the second inning, but Dempster buckled down and escaped any damage by getting Jordany Valdespin to line out to second and Josh Thole to ground out to short.
Sunday was Dempster's first start since June 15, and while the right-hander only threw 63 pitches, they were enough to be effective for five scoreless innings, over which he allowed just four hits while striking out four.
"It was two pretty painful at-bats for me," Thole said. "I didn't do a whole lot with him. He's a veteran guy. He's a sinkerballer. You know what you're going to get. He had good command of the strike zone with it, and coming off the DL, he's obviously pretty fresh."
The Mets had their final scoring chance in the sixth with Paul Maholm on the mound -- making his first Major League relief appearance -- but with Murphy on second, Ike Davis and Lucas Duda couldn't jump-start the offense.
The Mets and Cubs won't see each other for the rest of the season, and Collins said he's fine with that.
"Anybody can beat anybody at any given time, and they played us really well," Collins said. "Maybe it's a bad matchup for us."
The Mets still head into the All-Star break six games over .500. They are within striking distance of the National League East and remain competitive for an NL Wild Card spot. While Collins said his team could be in an even better spot if a few breaks over the first half had gone their way, he credited his players for maintaining a positive attitude amidst difficult losses like the one on Sunday.
"With our situation, everyone thought coming into the season that we were going to lose 162," Thole said. "We like where we're at right now."
Ethan Asofsky is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.