SAN FRANCISCO -- “Late Night” LaMonte did it again.

LaMonte Wade Jr. delivered a walk-off single in the bottom of the ninth inning Thursday night to lift the Giants to a 5-4 win and complete a three-game sweep of the D-backs at Oracle Park. The dramatic win lowered the Giants’ magic number to clinch the National League West to two with three games left to play, leaving them firmly in control of their own destiny as they head into the final weekend of the regular season.

• Box score

San Francisco will have the opportunity to clinch its first division title since 2012 as soon as Friday with the combination of a win over the Padres and a Dodgers loss to the Brewers.

• Games remaining: Three vs. the Padres
• Standings update: Two games ahead of the Dodgers
• Magic number for division title: Two

The Giants trailed by three runs following a disastrous first inning, but they erased two deficits behind Brandon Crawford's 24th home run of the year -- a solo shot to the opposite field in the fourth inning -- and Buster Posey's game-tying double off old friend Madison Bumgarner in the fifth inning.

That set the stage for Wade’s latest late-game heroics. With the game tied, 4-4, in the bottom of the ninth, Wilmer Flores doubled off the left-field wall to put the winning run in scoring position with one out. The D-backs then intentionally walked Donovan Solano to bring up pinch-hitter Curt Casali, who drew another free pass to load the bases.

Wade stepped up to the plate mired in an 0-for-19 funk, but he once again lived up to his nickname, shooting a 1-2 sinker from lefty reliever Joe Mantiply past a diving Pavin Smith at first base to score pinch-runner Steven Duggar from third and help the Giants secure their 105th victory of the year, one shy of matching the 1904 New York Giants for the most wins in franchise history.

“Honestly, I was just happy to put the ball in play,” Wade said. “I’ve been throwing away a lot of at-bats, so it just felt good just to get a hit.”

Wade is now 13-for-23 (.565) with 12 RBIs in the ninth inning this season. His six game-tying or go-ahead hits in the ninth are the most by any MLB player in a season in the past 40 years, according to STATS.

“I think, overall, he’s a really calm hitter,” Posey said. “I think that helps. I think anytime you can slow things down in a big situation, it’s an advantage. Also, success breeds confidence, and he’s had a lot of success in those situations. I’m sure he feels like he’s going to come through the next time up.”

The Giants improved to 17-2 against the last-place D-backs this year, but they had to dig deep to come out on top again on Thursday.

Starter Scott Kazmir recorded only one out before departing with a right hamstring strain in the first inning, but the Giants received a herculean effort from their bullpen, as Kervin Castro, Johnny Cueto, Zack Littell, Dominic Leone, José Álvarez and Tyler Rogers combined to deliver 8 2/3 innings of one-run ball to keep San Francisco within striking distance.

Cueto, who was activated off the injured list after missing a month with a right elbow strain, gave up one run over 2 1/3 innings in his first career relief appearance, while Rogers tossed two shutout innings to earn his seventh win of the year.

“We were going to grind our way through that game,” manager Gabe Kapler said. “We’ve talked all year about using the ‘resilient’ word to describe this team, but that’s precisely how I’d kind of describe them in this game.”

With the division title within reach, the Giants are also starting to push Posey, who started behind the plate for the third consecutive game and finished 1-for-3 with two RBIs. Posey shared a nice moment with Bumgarner in the top of the first, tapping his longtime batterymate on the leg with his glove when the former Giants ace stepped up to the plate and received a rousing ovation from the 27,503 fans in attendance.

“I think when you have as much history with somebody as I do with him, you try not to overthink it too much,” Posey said of facing Bumgarner. “I know what his tendencies are to certain hitters, and he knows that, as well. You can kind of get yourself spinning a little bit if you keep going down that path, so for me, I really tried to simplify it and see the ball and put a good swing on it.”

While the Giants’ success has stunned many outsiders, Bumgarner said he isn’t surprised to see his old club defying expectations once again.

“It’s pretty crazy,” Bumgarner said. “It’s pretty incredible to see. I know people counted them out all year and a lot of people can’t understand it or make sense of it. I’ve been on that side when people are saying the same thing. I know how dangerous the Giants are in general when they get in the postseason. I’ve obviously seen that a time or two. Something about that uniform, I don’t know.”