SAN FRANCISCO (AP) — Matt Chapman hit a grand slam in the first inning to lead the struggling San Francisco Giants to a 5-1 victory over the Cincinnati Reds on Saturday.

The Giants had lost eight of 11 games coming into the contest and were averaging less than three runs over their last 15 before Chapman provided more than that with one big swing in the first against Nick Lodolo (3-2).

“It means a lot,” Chapman said. “We’ve been grinding lately, not playing our best baseball. So to be able to jump out early like that was huge. I think we can build off a game like today.”

Chapman came to the plate with two outs in and sent a drive over the bullpen beyond the fence in left-center to give San Francisco a 4-0 lead.

Mason Black made the lead stand up by allowing only one run in 4 1/3 innings in his home debut, giving up a solo homer to Elly De La Cruz in the fourth.

“When you can get a lead like that hopefully it takes some pressure off the rest of the guys,” Chapman said. “Not when you’re up 4-0 you think you’re going to win the game, but it gives you a good cushion.”

The bullpen did the rest, sending the Reds to their ninth loss in 10 games.

Taylor Rogers (1-1) replaced Black with two runners on in the fifth. He got out of the jam by striking out pinch-hitter Stuart Fairchild with the bases loaded to earn the win.

Black was helped by outfielder Heliot Ramos, who threw out two runners from right field trying to stretch hits into doubles and then made a diving catch in left field in the fifth inning.

Ramos threw out Will Benson in the second and Jake Fraley in the fourth and then robbed Benson of a hit after moving spots in the fifth inning. Mike Yastrzemski replaced Ramos in right field and threw Jeimer Candelario out trying to stretch a hit into a double to end sixth.

“Over the course of the year we’re going to make base-running mistakes,” manager David Bell said. “Today I didn’t consider those mistakes. When the other team makes plays like that, makes perfect throws, you can’t wait around to find out. Today, they got it done.”

TRAINER’S ROOM

Reds: LHP Alex Young (back) retired all three batters on a rehab assignment at Triple-A Louisville on Friday and is expected to pitch again in the minors Sunday.

Giants: LF Michael Conforto left after hitting a single in the fourth inning with tightness in his right hamstring. He is day to day. … CF Austin Slater was placed on the seven-day concussion list after crashing into the wall Friday night. Manager Bob Melvin said Slater was reporting some “fogginess” the morning after. … C Patrick Bailey was reinstated from the concussion list and started. … Utilityman Brett Wisely was recalled from Triple-A Sacramento and C Jackson Reetz was optioned back to the River Cats.

Cincinnati						San Francisco
	ab	r	h	bi			ab	r	h	bi
Friedl cf	4	0	0	0		Estrada 2b	4	0	1	0
De La Cruz ss	3	1	1	1		Wade 1b	3	1	1	0
Ford dh	2	0	0	0		Bailey c	3	1	1	1
Fairchild ph-dh	1	0	0	0		Flores dh	4	0	0	0
Capel ph-dh	1	0	0	0		Ramos rf-lf	3	1	0	0
Steer 1b-lf	3	0	1	0		Chapman 3b	4	1	2	4
Fraley rf	4	0	3	0		Conforto lf	2	0	1	0
Stephenson c	4	0	0	0		Ystrzemski pr-rf	2	0	0	0
Candelario 3b-1b	3	0	1	0		Schmitt ss	3	0	0	0
Benson lf	2	0	1	0		Fitzgerald cf	3	1	1	0
Espinal ph-3b	1	0	1	0
India 2b	3	0	0	0
Totals	31	1	8	1		Totals	31	5	7	5

Cincinnati	000	100	000	—	1
San Francisco	400	000	10x	—	5

E–De La Cruz (8), Bailey (3). DP–Cincinnati 0, San Francisco 1. LOB–Cincinnati 9, San Francisco 5. HR–De La Cruz (9), Chapman (5). SB–Fraley (6). SF–Bailey (3).

	IP		H	R	ER	BB	SO

Cincinnati
Lodolo L,3-2	6		5	4	4	1	6
Suter	1		2	1	1	0	2
Farmer	1		0	0	0	0	1

San Francisco
Black	4	1-3	4	1	1	2	2
Ta.Rogers W,1-1		2-3	0	0	0	0	2
Walker H,4	1		2	0	0	0	1
Miller H,5	1		0	0	0	1	0
Ty.Rogers	1		1	0	0	0	1
Hjelle	1		1	0	0	0	1

HBP–Black (Steer), Ta.Rogers (De La Cruz), Miller (Friedl), Suter (Wade).

Umpires–Home, Larry Vanover; First, David Rackley; Second, Nate Tomlinson; Third, Chris Segal.

T–2:35. A–37,321 (41,915).