"That home run was huge," manager Don Mattingly said of the shot that gave Ethier 600 RBIs in a Dodgers uniform. "It changes the game and gets us going.
"It was questionable if he was going to play today. He hung in there and played."
Ethier said he "just kind of took it easy" in pregame preparation, and said the training staff did a good job getting him ready.
"There's something going around on this team now," Ethier said, referring to the flu, which also limited reliever J.P. Howell's availability the past two days -- although Howell warmed up Saturday in case he had to pitch to just one hitter.
The other guy who hung in for the Dodgers was starting pitcher Dan Haren (3-0). A Hanley Ramirez error led to three unearned runs of the four the D-backs scored off Haren in the third inning. But that's all Arizona managed against him until the eighth, when Haren came out after 100 pitches.
Brian Wilson got the last two outs of the eighth, but gave up a two-run double to Martin Prado, before Kenley Jansen came on in the ninth for his sixth save.
"[Haren] rebounded from that, and kept going," Mattingly said. "He was really good for us, gave our bullpen the shot it needed."
Friday's 12-inning game and the flu bug circulating, especially among the relievers, made Haren's 7 1/3-inning stint crucial.
"That inning when they got four runs, it seemed like anything that could go wrong did," Haren said. "I was able to keep them at four, and our offense really stepped up. Once Ethier hit that home run, I knew it was going to be a tight one."
Matt Kemp, who had a two-run double to cap the Dodgers' five-run fifth for an 8-4 lead, said Haren "did a great job again, hitting his spots, doing what he needed to do to win the game."
D-backs right-hander Mike Bolsinger (0-1), making his Major League starting debut, retired the first eight Dodgers and held them to one hit through three innings.
"I thought, anytime we're going against a guy most of us haven't seen before, the second or third time through the lineup might be different," Haren said.
"The second time through, we got a chance to see him," Ethier said. "Guys could go up and make their adjustments."
Bolsinger said: "First time through the order was good, but I kind of got away from my game plan a little bit. I left some balls up and when you do that up here, there's consequences. It's how you respond to it. Each time I've been out there, I've kind of learned."
Adrian Gonzalez and Kemp singled ahead of Ethier's homer. Gonzalez extended his hitting streak to a National League-best 14 games, and addded a two-run single in the fifth to put the Dodgers ahead, 6-4.
Besides Ethier, the other Los Angeles Dodgers to reach 600 career RBIs were Steve Garvey (992), Eric Karros (976), Willie Davis (849), Ron Cey (842) and Bill Russell (627).
"It's been a good ride," said Ethier, who joined the Dodgers in 2006. "I'm looking forward to a lot more RBIs here."