Starlin Castro hit a home run and the Cubs batted around in a four-run seventh inning to beat the Miami Marlins 5-1 in a rain-shortened game Wednesday night.Heavy rain began falling with Miami batting in the top of the eighth and the teams never returned to the field. The game was called after a 1-hour, 17-minute delay. Castro hit his eighth home run of the season off Marlins starter Josh Johnson (5-7) leading off the fourth. Jeff Baker highlighted a seventh-inning rally with a two-run, pinch-hit double with the bases loaded.James Russell (3-0) pitched a scoreless seventh to earn the victory in relief of Jeff Samardzija, who struck out nine in five innings. Jose Reyes homered for Miami and Emilio Bonifacio had three hits, falling a home run shy of the cycle. The Cubs rebounded from a slow start to move to 13-5 over their past 18 games. They have won nine of their past 11 at home. Johnson retired nine of the first 10 batters he faced before Castro led off the fourth with a home run. Miami’s big right-hander responded by striking out the next three. Johnson was economical until trouble found him in the seventh. Alfonso Soriano singled to lead off and advanced to second on a wild pitch. He scored on Geovany Soto’s chopper over the head of Hanley Ramirez. Darwin Barney followed with a single to chase Johnson.Mike Dunn fared no better in relief, surrendering hits to the first two batters he faced, including the Baker’s double. David DeJesus’ sacrifice fly capped the four-run inning. Johnson was charged with four runs over 6 1/3 innings. He struck out five and walked one to continue an inconsistent season. He gave up seven earned runs in five June starts, but has allowed 14 runs in three starts in July.By contrast, Samardzija was effective for a third consecutive outing, allowing one run over five innings.Reyes ripped an 0-2 delivery over the wall in right field leading off the third to put the Marlins up 1-0. It was his fourth home run of the year.He got out of a jam in the fifth despite Bonifacio’s leadoff triple. Logan Morrison hit a grounder with the infield in, but Soto bobbled the throw on a botched rundown to put runners at second and third. Samardzija struck out Ramirez and got Greg Dobbs to ground out to end the threat.Samardzija was lifted for a pinch-hitter in the fifth. He finished with nine strikeouts and two walks, scattering six hits.After a rough June, Samardzija has given up only five runs in 19 innings this month. Marlins manager Ozzie Guillen was again given a villain’s welcome by the home crowd in his return to Chicago. After visiting the mound to remove Johnson in the seventh to a rain of boos, Guillen paused for a moment to banter with fans before disappearing into the visitor’s dugout.

NOTES—The Marlins activated RHP Edward Mujica (broken toe) from the 15-day DL. RHP Ryan Webb was optioned to Triple-A New Orleans. … Cubs OF Jorge Soler will make his minor league debut on Thursday as a DH in the rookie league in Arizona according to GM Theo Epstein. The 20-year-old Cuban prospect signed a nine-year, $30 million contract on June 30.