On Sunday after two wins in San Francisco, Reds fans had fanciful thoughts that they could sweep the National League Division Series.

By Tuesday's Game 3 loss, the hubris turned into cautious optimism.

After Wednesday, when the Reds were handed a deflating 8-3 Game 4 loss by the Giants, everything has suddenly boiled down to one thing: Survival.

It's a feeling the Giants have had for three days already, and now the Reds are joining them.

There will be a deciding Game 5 finale at Great American Ball Park on Thursday (1 p.m. ET on TBS), with the winner advancing to the NL Championship Series and the loser going home for the winter.

"It's probably hard for them to believe that we were up 2-0 out there," said manager Dusty Baker.

"So they reversed on us what we did to them out there, and we have a big game, the rubber match, tomorrow. It won't matter, if we win tomorrow, it doesn't matter how many games you were up. But you know, they're a quality team, and we knew it was going to be a fight when we got here."

Added to the NLDS roster to replace the injured Johnny Cueto, Mike Leake did not step up with a savior-like spot start as Cincinnati had hoped. Leake gave up five runs and six hits, including two home runs, over 4 1/3 innings and left trailing by a 5-2 score.

As 44,375 fans looked on, they were rendered almost catatonic at the start when Angel Pagan hit Leake's second pitch of the game for a no-doubter of a home run to right field.

Fortunately for the Reds, Giants starter Barry Zito was having trouble locating. Unfortunately for the Reds, they didn't find enough ways to take advantage. Zito gave up a Joey Votto two-out single and three straight walks in the bottom half of the first, including one to Todd Frazier that forced home a run.

The Giants struck quickly again in the second inning as second batter Gregor Blanco belted a two-run homer to right-center field for a 3-1 lead. In the bottom half, Zito gave up a pair of two-out singles but got Votto to fly out weakly to left field to end the inning.

"He didn't start off very well in the first couple of innings, and then he settled down there," said Baker of Leake's start. "For a couple of innings, he threw the ball excellent."

In the bottom of the third, Ryan Ludwick's leadoff homer on Zito's 1-2 pitch closed the deficit to one run. And after a two-out walk, Zito was given an early hook with 76 pitches in 2 2/3 innings.

After a leadoff infield hit by Zack Cozart against George Kontos in the fourth, Giants skipper Bruce Bochy stayed in survival mode by calling on a situational lefty, Jose Mijares, to face Votto.

Mijares struck out Votto, who remained without an RBI in the series. Then Bochy turned the game over to Tim Lincecum, who struck out Ludwick to end the inning and begin a stretch of domination.

San Francisco had a stretch where eight of nine were retired by Leake but attacked in the fifth.

Following Joaquin Arias, Pagan lined a double to right-center field, snapping the Giants' 0-for-14 series skid with runners in scoring position. After a sacrifice, Leake was pulled and Pablo Sandoval's sacrifice fly off Sam LeCure made it a three-run game.

"Those couple of innings, and that one inning, it only took four pitches to double, hit, another double. So he wasn't real sharp," said Baker of Leake. "He was getting the ball up in the middle of the plate. When he does that, generally speaking, like most pitchers, he gets hit. Usually his ball is down.

"Like I said, he was throwing strikes. He wasn't walking them. He wasn't throwing quality strikes."

Drew Stubbs hit a leadoff double off of Lincecum in the sixth and later scored on Brandon Phillips' sacrifice fly. It was the only run scratched out against the ex-Giants ace as Lincecum rolled over 4 1/3 innings of work.

The game blew open on Reds reliever Jose Arredondo's watch, however, as the Giants used two doubles and a two-run home run by Sandoval to make it a five-run game.

What a reversal of fortune for a Reds team that allowed only 12 hits and four runs over the first three games. On Wednesday alone, the Giants belted out 11 hits, with eight going for extra bases. The Reds, meanwhile, were 0-for-7 with runners in scoring position and left 10 on base.

Since Division Series play began in 1995, a team with a 2-0 series lead advanced 38 of 42 times. The four exceptions were American League clubs, with the last being the 2003 Athletics.

NL clubs with 2-0 NLDS leads were 21-0 in advancing.

Mat Latos will get the ball in Game 5 for Cincinnati against the Giants' Matt Cain. It will be all hands on deck Thursday for both teams, but it will be the Reds who try to avoid a dubious distinction.

"We feel comfortable with Latos throwing tomorrow," Baker said. "The main thing is we left a lot of runners on base early in the game. We had a lot of opportunities early. We had Barry Zito on the ropes quite a few times. So the main thing is just come out fightin'. That's what it's about. Tomorrow is the final fight."