By Jeremy Kahn

SAN FRANCISCO-Josh Harrison did something in the top of the first inning that he never accomplished as a big leaguer.

Harrison hit a leadoff home run in the top of the first inning, as the Pittsburgh Pirates defeated the San Francisco Giants 3-1 before a crowd of 42,242, the 304th consecutive sellout at AT&TPark.

It was the first career leadoff home run for the third baseman, and his eighth home run of the season.

This continued until April 15 against the Los Angeles Dodgers and the Arizona was the Giants fifth consecutive loss, with their last win coming on Wednesday night against the Philadelphia Phillies, when Hunter Pence hit a three-run double in the top of the ninth inning.

If you wanted to know the last time that the Giants lost the first four games of a home stand, you will have to go back to when the ballpark first opened on April 11, 2000 to the Los Angeles Dodgers and the Arizona Diamondbacks.

Despite losing those opening five games, the Giants would go on to win the National League West for the second time in four seasons.

Francisco Liriano went seven innings, allowing one run on four hits, while walking one and striking out 11, as he won for just the third time this season against seven losses.

To make matters even worse, Hudson allowed a two-run home run to Travis Snider in the top of the second inning that proved to be the margin of victory for the Pirates.

Michael Morse hit his first home run at AT&TPark since May 15, when he took a Francisco Liriano over the left field wall, as he led off the bottom of the second inning.

Buster Posey went three-for-four for the Giants in the losing effort, as he picked up his third hit of the game in the bottom of the ninth inning off of Pirates closer Marc Melancon.

Unfortunately for the Giants, Posey was stranded on the base paths, as Pablo Sandoval flew out to the warning track in right, then Morse struck out for the third consecutive time and then newly obtained Travis Ishikawa struck out to end the game.

Despite allowing the two home runs in the first two innings, Hudson did settle down, as he went seven innings, allowing three runs on six hits, walking one and striking out two.

Rookie Andrew Susac, who was recalled on Saturday after Hector Sanchez was placed on the disabled list with a concussion, reached base for the first time as a major leaguer in the bottom of the seventh inning, as he walked off of Liriano.

Adam Duvall was optioned to Fresno and Tony Abreu was designated for assignment; and in their place, the Giants have purchased the contract of Ishikawa from Fresno and recalled Juan Perez.