By Annie Ross

Justin Bour hit two home runs and the Miami Marlins completed their first series sweep of the season by beating the woeful Phillies 10-2.

Marcell Ozuna hit his 14th homer for the Marlins (21-30), who have won four games in a row, their longest winning streak since last July. Dan Straily (4-3) struck out 10 , allowed one earned run in 6 2/3 innings, and won his third start in a row.

With the franchise for sale, the Marlins are on pace to finish last in the NL in attendance for the 12th time in the past 13 years. But lately they’re giving fans more to cheer about.

Miami swept three games against division rival Philly for the first time since 2012.

“Two teams that were both struggling, pretty much even,” Phillies manager Pete Mackanin said. “They came out on top; we came out on the bottom. We need a series like they just had against somebody.”

The Phillies (17-34), off to their worst start since 1961, went 6-22 in May. That’s their fewest wins in a month since June 1997.

The Marlins, by contrast, finished the month strong after a stretch when they went 4-19.

“We’re playing better,” manager Don Mattingly said. “Hopefully our best baseball is ahead of us.”

The Marlins are winning with offense, scoring 73 runs in the past 10 games, and the latest victory came without slugger Giancarlo Stanton, who rested while recovering from hamstring cramps. He’s expected to return to the lineup Thursday.

Bour hit a solo homer in the fifth and a two-run homer in the sixth to finish with 11 homers in May.

“We have a dangerous lineup one through nine,” Bour said. “We’re realizing just how good this lineup can be, and the runs we can put up, and guys aren’t trying to do too much.”

Ozuna borrowed teammate Ichiro Suzuki’s bat to homer Tuesday, stuck with it to hit a two-run homer in the first inning Wednesday and then said he was retiring it. Ozuna went on to collect two more hits with his own bat.

Aaron Nola (2-3) lost his third start in a row. He gave up four runs and needed 73 pitches to get through three innings — his shortest outing of the year.

“Too many pitches for me,” Mackanin said. “I didn’t want him to get hurt and throw 100 pitches in four innings.”

The Phillies were held to less than three runs for the ninth time in the past 11 games. They were outscored 21-5 in the series.