SAN FRANCISCO -- Football coaches often are warned: Don't take points off the board.

But when it happened to San Diego Padres manager Andy Green in a baseball game Tuesday night, he had no choice.

Johnny Cueto outdueled James Shields in a battle of former Kansas City Royals World Series aces, lifting the San Francisco Giants to a 1-0 victory over the San Diego Padres in a game the Padres once led 1-0.

Denard Span doubled home Brandon Crawford with the only run of the game that counted in the fifth inning as the Giants won for the fourth time in five games after opening their current 10-game homestand with four consecutive losses.

The Padres, who fell 5-4 to the Giants in the series opener Monday night, dropped a seventh straight at AT&T Park, and had baseball's replay rules to blame.

Cueto (4-1) continued the brilliant start to his first year with the Giants, striking out 11 in a complete-game, seven-hit shutout.

After stranding three Padres in scoring position in the first five innings, he finished with a flourish, saving five strikeouts for the final four innings, allowing only two hits during that stretch.

"That's basically my game," Cueto said of giving the Giants' bullpen a rest. He's gone at least seven innings in all five of his starts this season.

"The manager asked me how I felt (after the eighth inning) and I said I felt good. As a pitcher, it's always what you want -- to pitch a shutout."

Cueto walked only one batter in the game, giving him just five in his five starts.

The win was the 100th of his career, making him just the 12th Dominican-born pitcher to achieve the milestone.

"That's a special number for a pitcher," he said.

Cueto pitched two shutouts last season, one each for the Cincinnati Reds (July 7 at Washington) and Royals (Aug. 8 vs. Detroit).

The 11 strikeouts were his most since he recorded 12 in just six innings against the Los Angeles Dodgers on June 11, 2014.

"I can't say I'm surprised with how he's doing because he'd had that kind of career," Giants manager Bruce Bochy said. "That's why we wanted him here."

Shields (0-4) was nearly as good. He allowed only three hits in seven innings, but the one run he gave up was one too many.

He walked four and struck out two.

Shields was supported by no runs for the third time in his five starts this season.

"He threw the ball every bit as well as Johnny Cueto," Green said of Shields. "If you look pitch by pitch, he probably pitched a better game than Johnny Cueto."

Interestingly, the Padres actually got on the scoreboard first in the top of the fifth, only to have the run erased on video replay.

Singles by Alexei Ramirez and Shields sandwiched a walk to Adam Rosales to load the bases with one out.

Jon Jay then grounded to shortstop, and the Giants went for a second-to-first double play. When Jay was called safe at first base, it appeared Ramirez scored the first run of the game.

However, the Giants challenged the call, and after a short review, the ruling was overturned, reverting the score back to 0-0.

"It's good to see us get one," Bochy said of the replay, which he felt worked against him team in Monday's 5-4 win. "He looks out, but after what's happened to us this week, you don't know.

"That's a big moment."

The Padres' Green didn't dispute the overturn, but did acknowledge its significance.

"If we had scored the run instead of them, he (Shields) would have had the opportunity to pitch the complete game that Johnny Cueto did," he said. "We were unable to capitalize on our opportunities."

Crawford batted three times against Shields and was never retired, sandwiching his fifth-inning single with a hit by pitch and an intentional walk.

Brandon Belt and Hunter Pence also doubled for the Giants, who totaled three doubles among their four hits.

Ramirez had two of the Padres' seven hits and Wil Myers extended his hitting streak to 11 games with a fourth-inning single. San Diego out-hit the Giants 7-4.

"We faced a pretty good pitcher on the other side," Shields said. "He got out of some jams. Bottom line: We have to be better overall."

The Giants ended Shields' no-hit bid, and subsequently his shutout, in the bottom of the fifth inning.

Crawford led off with a single, the Giants' first hit, and was sacrificed to second.

With two outs, Span hit a deep drive that Padres right fielder Matt Kemp stopped chasing. The ball wound up hitting low on the wall, certainly in a catchable area, but turned into a run-scoring double.

The Giants threatened to have a big inning, but Padres left fielder Melvin Upton Jr. made a sliding catch with two on and two outs on a liner by Matt Duffy, ending the uprising.

NOTES: Giants starting pitchers have gone 9-1 with a 1.75 ERA in the last 11 matchups with the Padres in San Francisco. ... The complete-game shutout was the 14th of Cueto's career. ... Cueto's 100th win tied him with RHP Mario Soto for 11th among Dominican-born pitchers. His next win would move him into a tie for 10th with RHP Ubaldo Jimenez. ... C Austin Hedges, a Padres farmhand at Triple-A El Paso, will undergo surgery to repair a fractured hamate bone in his left hand. He is expected to be out close to two months. ... The Padres purchased the contract of LHP Michael Kirkman from El Paso while optioning INF Jose Pirela to the minors. As part of the transaction, the club designated RHP Cory Mazzoni for assignment.