BOSTON – The heaviest of the daylong rain came hours too late Wednesday for the Boston Red Sox.

In a game delayed four times for a total of almost 2½ hours and called before the bottom of the eighth inning, the Red Sox suffered through another poor outing by John Lackey in a 5-1 loss to the San Diego Padres.

The Red Sox dropped their second straight for the first time this month, collecting 10 singles, but letting Clayton Richard off the hook a few times early.

The game was delayed 35 minutes at the start, then 38 minutes in the top of the third inning and 31 more in the middle of the fifth. By that time the Padres had scored four runs off a wild Lackey in the fourth.

Lackey (5-6) had his three-game winning streak end with an outing that lasted 3 1/3 innings and raised his ERA to 7.36. He gave up a leadoff home run to Will Venable, but pitched out of trouble in the second and third before it all came apart during a four-run fourth.

Lackey hit two batters, one with the bases loaded, and issued a bases-loaded walk for another run.

“He went back out after the rain delay and just looked like he lost his feel,” Red Sox Manager Terry Francona said. “I don’t think the conditions were good for either pitcher, but he just lost his feel. He was scattering some pitches.”

Lackey yielded all five runs on just four hits, leaving to a brief chorus of boos.

Asked about the conditions, he said, “They weren’t great. I don’t think I’ve ever hit anybody with the bases loaded before.”

The Red Sox had outscored the opposition 32-11 during Lackey’s three-game winning streak.

For the second straight game the Sox wasted numerous chances, in their final home game before a nine-game trip that will take them to Pittsburgh, Philadelphia and Houston.

On Tuesday, they had four runs on 13 hits and went 3 for 13 with runners in scoring position. They followed that by going 2 for 7 with runners in scoring position Wednesday.

David Ortiz stranded seven base runners in three at-bats.

Adrian Gonzalez went 4 for 4 against his former team to raise his major-league leading average to .359 and drove in Boston’s run. In three games against his old team, he went 8 for 14 with four RBI and two runs.

Richard received some support for a change, lifting San Diego to its second straight win after a season-worst six-game losing streak. The Padres finished their trip at 3-6.

The Red Sox lost for the fourth time in 18 games and dropped consecutive games for the first time this month.

The start was delayed 35 minutes. Play was halted with two outs in the top of the third for 38 minutes and again in the middle of the fifth, that delay lasting 31 minutes. The final one in the middle of the eighth was 40 minutes.

In the third delay, crew chief Ed Rapuano called for the tarp, but never left the field when he asked for the grounds’ crew to take it off a few minutes later while the rain appeared to be falling at a similar rate.

The Padres, who entered the day with the majors’ worst batting average at .233, had just seven hits.

Richard (3-10) lasted through two of the delays, giving up one run and eight hits over five innings to snap a five-game losing streak. He lost five of his last six starts with a no-decision in the other despite holding opponents to three or fewer runs five times.

Venable hit the game’s seventh pitch into the right-field seats for his first homer of the season and the first leadoff shot of his career.

The Padres took advantage of Lackey’s wildness, chasing him with four runs in the fourth. Orlando Hudson drew a leadoff walk and Anthony Rizzo was hit by a pitch before Cameron Maybin laid down a well-placed bunt for a single.

Lackey threw a wild pitch to allow a run and walked Venable, forcing home another. He also hit Jason Bartlett in the back with a 2-2 pitch with the bases loaded and Chase Headley had an RBI single, making it 5-0.

Gonzalez’s RBI single cut it to 5-1 in the fifth.

NOTES: Francona said he’s still not sure whether right-hander Josh Beckett, who missed Tuesday’s start with a stomach ailment, will be able to start Saturday in Pittsburgh. “He’s really sick,” Francona said. “We’re going to have to play this by ear. He’s got a good old-fashioned case of the flu.” Left-hander Andrew Miller is likely to start if Beckett can’t. Francona appears to be leaning toward playing first baseman Gonzalez in right field during Boston’s nine-game interleague trip, allowing Ortiz to play first. “I don’t want David to go 11 days without playing,” he said. Padres Manager Bud Black said Tim Stauffer, Dustin Moseley and Cory Luebke will start the three home games against Atlanta this weekend. Luebke will be making his first start of the year. Hudson stole his career-best 11th base.