Updated

Edwin Jackson pitched six innings of one-run baseball and the Chicago Cubs defeated the New York Mets, 6-3, in the opener of a three-game series at Citi Field.

Jackson (3-8) gave up five hits and three walks while striking out seven. He earned consecutive wins for the first time since Aug. 30-Sept. 4, 2012. Kevin Gregg pitched a flawless ninth to notch his eighth save.

David DeJesus delivered a three-run triple, but left the game in the bottom of the third with a strained right shoulder. He went after a ball by Juan Lagares but the ball dropped out of his glove and his shoulder collided hard against the center field wall. He writhed in pain as he was checked by team trainers but was able to leave the field under his own power. He is expected to go on the disabled list.

"He had a huge hit for us then made a gutsy play out there," said Chicago manager Dale Sveum about DeJesus. "He paid for it in the end and almost made a huge catch. Hopefully it's nothing major and he'll only be out a couple weeks."

Nate Schierholtz had a solo home run while Luis Valbuena and Darwin Barney contributed an RBI apiece for the Cubs.

Daniel Murphy drove in two runs and Lucas Duda had an RBI for the Mets, who have lost nine of their last 11 games.

Shaun Marcum (0-8), who tossed eight innings of relief on Saturday against the Marlins, got the start for the Mets. He pitched 5 2/3 innings, allowing all six runs on seven hits and a walk. He is the first Mets pitcher to start a season 0-8 since John Franco in 1998.

"I think Shaun is a professional," said Mets manager Terry Collins. "He knows you got to go and get the job done. He's pitched very well but he was off to a very bad start. You make a couple of bad pitches and it's going to hurt you."

Marcum gave up a home run to Schierholtz with two outs in the first.

An inning later, Marcum allowed four more runs. Anthony Rizzo and Dioner Navarro connected on back-to-back singles and Valbuena drew a walk to load the bases. Barney then singled to center, scoring Rizzo.

After Jackson struck out, DeJesus knocked a pitch that went over Lagares' head and off the center field wall, bringing all the runners home.

Following DeJesus' injury in the third, Marcum and Jordany Valdespin popped out, but Murphy's single to center plated Lagares.

The Cubs added one run in the sixth when Valbuena delivered a two-out RBI double that scored Rizzo.

In the seventh, Collin Cowgill hit a leadoff double to center, advanced to third on a wild pitch by James Russell and scored on Murphy's base hit.

After a single by David Wright, Duda smacked an RBI single. On the same play, Wright tried going from first to third, but a great throw by Alfonso Soriano beat him to the bag. Marlon Byrd struck out to end the inning.

Game Notes

Wright went 3-for-3 with a walk... Barney has played 51 errorless games at second base to start the season and is on a 54-game errorless streak dating back to Sept. 30, 2012 ... Rizzo went 3-for-4 and scored twice ... The Cubs will play 15 of their next 18 games on the road.