By Jeremy Harness

Through much of the past five years that has seen them win three World Series titles, the Giants’ bullpen has been known as a strength.

That was not the case Wednesday.

Handed a two-run lead in the bottom of the ninth, closer Santiago Casilla failed to get one batter out. He surrendered two straight singles to start the inning before Justin Bour took a Casilla fastball into the right-field for a walk-off three-run homer to send the Giants to a 6-5 loss to the Miami Marlins at Marlins Park on Wednesday.

After dropping the first two games of the series, the Giants hope to salvage at least one game Thursday before they head to Washington to face the Nationals for another three-game series.

Despite suffering through a three-run third inning, starter Chris Heston regrouped and was steady the rest of the way. He went six innings and gave up just those three runs on five hits. He walked three batters and struck out one and was in line to get the victory.

That’s because the Giants rallied for a pair of runs to take the lead in the sixth. Following a sac fly by Brandon Belt that scored a run, Brandon Crawford continued his hot streak by touching up starter Dan Haren for a solo homer that gave the Giants the one-run lead.

In the seventh, the Giants took advantage of a pair of errors by reliever Sam Dyson to get another run and bolster their lead to two.

Notes: Buster Posey took a foul tip off of his mask in the second inning, and the catcher eventually left the game four innings later. However, at press time, it was not immediately known whether or not Posey had suffered a concussion on the play.