BOSTON (AP) -- There was a little tension in Fenway Park when John Lackey's return from the disabled list began with a 27-pitch first inning.
Lackey quickly eased the fears - including some of his own - and pitched six solid innings for the Boston Red Sox in a 6-1 win over Houston on Sunday and completing a four-game sweep of the Astros.
Lackey (1-1) got his first win since Aug. 23, 2011. He missed all of 2012 after having Tommy John surgery on his right elbow, then spent most of the opening month on the disabled list with a strained right biceps.
''It feels good. It's been a long time,'' said Lackey, who allowed one run and five hits. ''It's been a lot of hard work to get back to this point and hopefully we can keep it rolling forward.''
Lackey performance was a welcome sight. His only other start this season ended early with Lackey walking toward the dugout in pain, holding his right arm. The soreness was in his muscle though, above the surgically repaired elbow, and only required a stint on the 15-day DL.
Almost better than getting the win for Lackey was getting through the start without pain.
''The elbow's fine,'' he said. ''I was relieved probably to know I'm going to get my next start, just to come out of it healthy more than anything.''
Lackey struck out four and walked two, both coming in the first inning and led to the only run Houston scored. He got in another jam in the sixth when the Astros loaded the bases with one out, but got himself out of it.
The Red Sox (18-7) tied the club record for wins in April and will have a chance to set a new opening-month mark Tuesday at Toronto.
Stephen Drew hit a two-run triple and David Ortiz drove in two runs with two hits, extending his hitting streak to 20 games dating back to last season. Ortiz has 11 RBIs and is batting .516 in eight games since returning to the lineup last weekend.
Bud Norris (3-3) struck out six for Houston and allowed five runs - three earned.
Two errors by shortstop Marwin Gonzalez led to two unearned runs in the fifth that put Boston up 5-1.
Houston has lost four straight and seven of nine.
''We've been battling and we wanted to put a 'W' up there. But we've got to put it behind us and get ready for the next day and try to end this skid,'' Norris said. ''It's early though. It's a long haul.''
Houston left nine runners on base and was 2 for 9 with runners in scoring position on Sunday. The Astros were just 5 for 38 in the series. They had a runner on third with two outs in the ninth, but Daniel Nava ended the game with a diving catch in right field.
Ronny Cedeno drove in Houston's only run with a single in the first after Lackey had walked Jason Castro and Carlos Pena with two outs.
The Astros loaded the bases with one out in the sixth on consecutive singles by Castro, Pena and Cedeno, but Lackey got himself out of the jam by striking out Fernando Martinez and getting Matt Dominguez to ground into a fielder's choice.
''I was hoping he'd get through five, but he battled. He found it and he was able to get through six,'' first baseman Mike Napoli said. ''It's going to mean a lot, especially when he pitches like that. We're going to need him. Hopefully he stays healthy. When he's healthy I've seen him do good things.''
The Red Sox also left the bases loaded in the first after Ortiz's RBI single scored Nava, who doubled with one out.
The missed opportunity didn't hurt Boston as the Red Sox scored twice in both the fourth and fifth innings.
Napoli led off the fourth with a blooper down the right field line and tried to stretch it into a double, but former pitcher Rick Ankiel's throw reached second well before Napoli and shortstop Gonzalez made the tag for one out.
The Red Sox still got two runs in the inning. Mike Carp and Jarrod Saltalamacchia hit back-to-back singles and scored easily when Drew - batting .136 coming in - tripled down the right field line and the Red Sox took their first lead at 3-1.
''We needed it,'' Drew said. ''Any time you can get two-out RBIs, it's huge. You put that with good starting pitching and good defense, that will win you ballgames.''
In the fifth, Gonzalez bobbled a grounder by Nava and his hurried throw sailed well over first baseman Pena, then the Boston dugout. Gonzalez got two errors - fielding and throwing - which led to another run when Dustin Pedroia drove in Nava with a double. Carp added a two-out double to score Pedroia for a 5-1 lead.
NOTES: The Astros are 2-11 against Boston all time and winless in seven games at Fenway Park. ... Houston's road trip continues Monday in New York, where the Astros open a three-game series against the Yankees. ... Jose Altuve went 0 for 4, ending his streak of reaching base in 17 straight games. ... The series sweep is the second this season for the Red Sox, who also swept Cleveland.