Los Angeles (21-10) set a modern major league record by winning its first 13 home games, a start fueled in large part by Ramirez.
However, the Dodgers have dropped their first two games - both at Dodger Stadium - since Ramirez was suspended 50 games for testing positive for a banned substance.
Los Angeles' offense didn't disappoint without its leading run producer in an 11-9 loss to Washington on Thursday night, but the Dodgers matched a season-low run total in a 3-1 loss to the Giants (15-13) on Friday night. They were 1-for-9 with runners in scoring position.
"Are we better with him?" third baseman Casey Blake said before Friday's game. "Yes we are, but we're still very, very good without him. What are you going to do, shut it down without him? No."
The Dodgers hope to find some answers soon. Ramirez isn't eligible to return until July 3 in San Diego.
The Giants (15-13) could be the team to benefit most from Ramirez's suspension. They're the only other team in the NL West with a winning record, and they've already made up two games on the Dodgers since Ramirez was banished.
Giants shortstop Edgar Renteria broke a 1-all tie with a sacrifice fly in the seventh inning Friday, and Pablo Sandoval drove in an insurance run with an infield single later in the inning as San Francisco improved to 13-0 when scoring first.
"They have a great lineup and Manny adds that much more to it. But it's still a great lineup without him," Giants starter Barry Zito said after San Francisco won for the third time in four games against Los Angeles after losing the clubs' first three meetings.
"That team's in first place for a reason. This is a big series for us, to come down here, make a statement and say, 'Hey, we're not going to roll over in this division.'"
The Giants will go for their third straight win with Jonathan Sanchez (1-2, 3.80 ERA) on the mound Saturday. The left-hander was reached for four runs in four innings of a 4-2 road loss to the Chicago Cubs on Monday after holding opponents without an earned run over his previous 12 2-3 innings spanning two starts and one relief appearance.
Sanchez is 0-1 with a 4.18 ERA in seven career games - four starts - against the Dodgers. He allowed two unearned runs in five innings of the Giants' 5-3 loss to them last Tuesday.
Eric Stults (3-1, 4.94) will take the ball for Los Angeles. The left-hander gave up two runs in a season-high 5 2-3 innings in a 7-2 win over Arizona on Monday. He's 1-2 with a 6.45 ERA in six games - five starts - against the Giants, including 1-1 with an 8.22 ERA in two starts this season.