Arroyo's seven innings marked his longest postseason outing in five starts and 13 appearances — and he couldn't have picked a better moment to do it.
Cueto threw all of eight pitches in Saturday's 5-2 win before leaving with back spasms, and Mat Latos and a patchwork pitching staff handled the rest.
Baker said he picked Arroyo for Game 2 here in part because the righty is susceptible to giving up home runs after he allowed 26 this year. And AT&T Park is "one of the most forgiving ballparks in baseball."
Arroyo thoroughly outpitched Madison Bumgarner to beat the Giants for the first time since 2008. He had gone 0-2 with a 2.42 ERA in four starts since, getting two no-decisions this season.
And he took the hard-luck loss in Game 2 against the Phillies in 2010 as the victim of a blown save.
Boy did he give the bullpen a break with this one. Baker might have left him in longer had it not been a long inning before.
"A no-hitter in this type of environment is nearly impossible," Arroyo said. "A win for the ballclub is the pinnacle, nirvana."
Cincinnati beat San Francisco's two best pitchers on the Giants' home field. Matt Cain lost Game 1.
Bumgarner had pitched a one-hitter June 28 against the Reds at home, but was nothing close to that dominant this time.
The last time Baker managed in a playoff setup like this season — with the higher seed opening on the road for the first two games — he was on the other end. In 1997, while managing the favored Giants, San Francisco lost the first two games in Florida and the Marlins completed a three-game sweep of the NL division series at Candlestick Park en route to the World Series title.
Baker has felt good about these Reds all along, even more so after recently missing 11 games while recovering from a mini-stroke, including when they clinched the NL Central.
"He's kind of the heartbeat of this team," Bruce said. "To have him back for the last series and starting the playoffs, especially in San Francisco, where he obviously has a ton of history and is a storied manager here, it's good. It gives us a vibe that's pretty easy to play for."
He is getting contributions from throughout his lineup and a ready-for-anything pitching staff.
On Saturday, it was Brandon Phillips with three hits and a two-run homer, and Bruce with a solo shot. The Reds added on late in Game 2 against the Giants' typically reliable bullpen with Bruce's eighth-inning double, a run-scoring triple from Drew Stubbs and an RBI single by Phillips.
Ludwick, who came in just 1 for 16 lifetime against Bumgarner, silenced the orange towel-waving sellout crowd of 43,505 AT&T Park in a hurry when he sent the first pitch of the second inning over the center-field wall.
The Reds sure made the Giants' pitcher friendly ballpark feel long-ball friendly the way they hit in these two games.
Many of the fans quickly made for the exits after the Reds went ahead 6-0 on Bruce's two-run double in the eighth.
"We need to go to their place and play aggressive and try to change the momentum," Giants second baseman Marco Scutaro said. "Keep fighting, you never know what's going to happen. Their momentum is really good right now."