PORTLAND — The Portland Sea Dogs (30-15) used a complete game in the first tilt and a five-run fifth in the second to sweep away the Binghamton Mets (24-20) 5-1 and 6-5 in a doubleheader Wednesday night at Hadlock Field. The wins send the Sea Dogs to a 9-4 record against the Mets this season.

The Sea Dogs scored right away off Luis Cessa (0-1) in his Double-A debut, and Keith Couch tossed the fifth complete-game of his career, leading the Sea Dogs to a 5-1 win in game one of doubleheader. Portland improved its record to 29-15, going 14 games over .500 for the first time since July 19, 2006 (55-41).

Couch improved his career record to 14-1 as a starter with Portland, scattering nine hits on one run over seven innings. Portland turned three double plays behind Couch, who walked one and fanned two.

Portland went to work in the first inning after the Mets took a 1-0 lead on a run-scoring fielder’s choice by Kevin Plawecki. Stefan Welch clubbed a three-run homer into the U.S. Cellular Pavilion, giving Portland a 3-1 lead. The homer was the second for Welch and his first since April 29.

Travis Shaw led off the third inning with a solo homer to center field off Cessa. Shaw homered for the third time this homestand, and is tied with Trenton’s Kyle Roller for the third spot in the league in homers, with nine. The Dogs added their final run in the fourth inning on a run-scoring double by Mookie Betts (1-for-2, BB, HBP).

Couch allowed a hit in six of seven innings, but held the B-Mets to 1-for-9 with runners in scoring position. The complete game was the fifth of his career, but his third with Portland

The Sea Dogs sent Wilfredo Boscan to the hill in game two against the Mets, but quickly found themselves in a 5-0 hole after the second inning. Wilfredo Tovar doubled and scored on Jayce Boyd’s fielder’s choice in the first to make it 1-0.

Derrik Gibson committed an error to start the top of the second, which gave way to four unearned runs in the inning, all scored with two down. Kyle Johnson delivered the first run with an RBI single, Matt Reynolds knocked home another with a single and Matt Clark capped off the inning with a two-run double, which made it 5-0 B-Mets.

Portland was held scoreless over the first two frames, but began a comeback with a run in the third. Shannon Wilkerson led off the inning with a double, and two batters later, it was Gibson who knocked him home with a double off the third base bag, which cut the deficit to four.

Binghamton starter Matt Bowman silenced the Sea Dogs in the fourth, but could not escape an onslaught in the fifth. Wilkerson began the inning with a single and moved to third on a Mookie Betts double. With one out, Shaw walked to load the bases and Welch followed with a two-run single to left to cut it to 5-3.

Bowman (3-2) retired Henry Ramos on a grounder to first, but walked Heiker Meneses to load the bases, which ended his outing. Chase Bradford was first out of the pen and faired no better against the bottom of the Portland order.

Mike Brenly greeted the reliever with an RBI single that plated Shaw and made it a one-run deficit at 5-4. Peter Hissey stepped in and took a first pitch fastball through the hole on the right side for a base hit that scored both Welch and Meneses and gave Portland the 6-5 lead.

Following Boscan’s outing on the hill, the Dogs called upon Robby Scott to put a stop to the bleeding. That’s exactly what the southpaw did. Scott (6-1) pitched three scoreless innings and allowed just two base runners, both on hits, in his outing and left in line for the win. Jose Valdez came on for the ninth and pitched it in scoreless fashion to wrap up the doubleheader sweep with his fourth save of the season.

The Sea Dogs and Mets get set for the finale of the six-game, four-day series tonight at 6 p.m. at Hadlock Field. Portland is slated to send Mickey Pena (3-0, 4.86) to the hill to be matched up against Rainy Lara (4-1, 4.05) of the Mets.