SAN FRANCISCO -- The Giants put on a show of resilience on Mother's Day, erasing three deficits to emerge with a hard-fought 6-5 win in Sunday afternoon's series finale against the Reds at Oracle Park.

San Francisco twice tied the game on two-run home runs from Pablo Sandoval and Brandon Belt before staging the decisive rally in the bottom of the eighth.

The Reds took a 5-4 lead after Tucker Barnhart drew a bases-loaded walk off left-hander Tony Watson in the top of the inning, but the Giants rallied to score two runs on RBI singles from Mac Williamson and Kevin Pillar. Pillar blooped a single to shallow center field to drive in Sandoval from second for the go-ahead run, helping to snap the Giants' three-game losing streak.

• Box score

"Next time, hit it in the gap," Sandoval told Pillar after the game.

Sandoval and Pillar combined to go 5-for-8 while swinging pink bats in honor of Mother’s Day.

“We love our moms,” Pillar said.

Here are three observations from Sunday’s series finale:

1. Bumgarner remains strong, but questions about the rest of the rotation persist
Left-hander Madison Bumgarner has anchored the Giants’ rotation all season, and he delivered another solid performance on Sunday, yielding four runs (two earned) while walking none and striking out seven over six innings.

Aside from a pair of unearned runs in the first inning, Bumgarner allowed only an RBI double to Nick Senzel in the second and a leadoff home run to former Dodger nemesis Yasiel Puig on an inside fastball in the sixth.

"He's a quick study," Bumgarner said, who lowered his ERA to 3.88 on the season. "It only took him seven years to learn how to hit that pitch."

• Bumgarner mocks Puig after giving up HR

While Bumgarner has remained a constant for the Giants, the rest of the rotation has taken a step back in recent weeks, leading to Dereck Rodríguez’s demotion to Triple-A Sacramento and Derek Holland’s move to the bullpen on Saturday. Tyler Beede is expected to get a second look in the rotation on Tuesday against the Blue Jays, and San Francisco is still mulling potential options for Wednesday’s game.

“We’re trying to make adjustments and doing all we can to get this rotation back in order,” manager Bruce Bochy said before the game. “Every season has its ups and downs, and right now, it’s the starting rotation. A couple of weeks ago, we wouldn’t think this would be this big [of] an issue with us. We’ll get it fixed. We’ll get it right.”

2. Sandoval keeps coming through
With Belt out of the starting lineup for the second consecutive game with right knee inflammation, Sandoval drew another start at first base Sunday and proceeded to go 3-for-4 with two RBIs and two runs scored. He collected his fourth home run of the season after clubbing a two-run shot off Reds right-hander Tyler Mahle to tie the game at 2 in the first inning.

Despite sporadic playing time, Sandoval has remained productive for the Giants, batting .282 over 36 games.

“He’s one of those guys that can sit and go up there and give you a good at-bat, whether it’s a pinch-hit or he gets his starts,” Bochy said. “I just liked the way he was swinging the bat. Belt probably could have played, but I just felt the way Pablo was swinging, we could give Belt another day. He goes out there and just puts together a tremendous game. The guy just has a knack at coming through when you need him.”

3. Rough day for Kratz
One day after being activated from the 10-day injured list, Erik Kratz started behind the plate for the Giants and endured a forgettable first inning, allowing Senzel to reach on catcher interference and advance to second on a passed ball.

Eugenio Suarez added a one-out single and stole second without a throw from Kratz, putting runners on second and third. José Iglesias subsequently delivered a two-out, two-strike single to knock in two unearned runs against Bumgarner.

Kratz, 38, opened the year as Buster Posey’s backup, but his spot on the roster has grown a bit tenuous following the arrival of fellow veteran Stephen Vogt. The Giants are currently carrying three catchers in Vogt, Kratz and Aramís García, but they will have to subtract a player from that group once Posey is ready to come off the seven-day concussion list, which could happen as soon as Wednesday.

Kratz, who went 0-for-2 Sunday to drop is batting average to .125 on the season, could be the odd man out, especially now that Vogt is healthy and swinging the bat well.