He also watched as the Cubs squandered a victory after a stellar first inning in their series opener with the San Diego Padres.
Visiting Chicago looks to avoid a fifth consecutive loss Saturday night as it faces a Padres team seeking a fifth victory in seven games.
The last-place Cubs (54-74) took a 6-0 lead before recording an out Friday, as Nate Schierholtz hit a three-run homer and Brian Bogusevic added a two-run triple.
They wouldn't score again, though, as San Diego rallied for an 8-6 victory. Chicago became the first team to score six runs before an out was made and lose since Pittsburgh's 9-8 loss to Cincinnati on May 18, 2006.
"It's not the ideal start, but there is nine innings of baseball left and anything can happen,'' said Padres infielder Jedd Gyorko, who hit a pair of homers and drove in a career-high four runs. "We had great at-bats up and down the lineup.''
Chicago's Junior Lake had three hits and is 12 for 26 during a six-game hitting streak, though that didn't make the loss any easier for Cubs manager Dale Sveum.
"They beat our butts the last eight innings,'' Sveum said.
The Cubs have dropped six of seven, with Samardzija (7-11, 4.12 ERA) recording the only victory Monday against Washington. After Chicago gave him only four total runs over his previous four starts, Samardzija benefited greatly from the offense scoring three runs in the first, saying it helped him settle down.
Samardzija had gone 0-2 with a 9.39 ERA over his previous three starts before tossing a six-hitter in the 11-1 win.
"All the hard work I do in the offseason and during the year, to see it paying off with feeling good in the eighth and ninth inning and 100 pitches is what it's all about," Samardzija said.
The right-hander struck out eight and gave up three runs in five innings of Chicago's 5-3 win over the Padres on April 29, and he's 1-1 with a 3.32 ERA in three career starts against them.
San Diego (58-70) has won five straight home meetings with the Cubs after Will Venable went 3 for 4 with three RBIs on Friday, including a tiebreaking solo homer in the seventh.
The Padres look to win a third straight with help from Eric Stults, who is seeking his first victory since beating San Francisco on July 14.
Stults (8-10, 3.70) is 0-3 with a 4.75 ERA over his last six starts after giving up three runs in 6 2-3 innings of San Diego's 4-3 win over the New York Mets on Sunday.
"I felt better than I did in my last start in Colorado," said Stults, referring to when he allowed five runs and 11 hits in 4 2-3 innings Aug. 13. "It's always nice to be at home."
The left-hander has seemed to feel that way all season, going 5-2 with a 2.50 ERA in 12 starts at Petco Park as opposed to 3-8 with a 4.93 ERA on the road.
Stults gave up two runs in 6 2-3 innings of the Padres' 4-2 win May 2 at Wrigley Field. The Cubs rank 28th in the majors against left-handers this season, hitting .230, and Saturday will be their first look at a southpaw starter in 16 games.