Hader came on with two on and one out in the ninth after Nick Martinez (3-3) walked Luis Matos and gave up a single to Patrick Bailey.
Pinch hitter Casey Schmitt worked the San Diego closer for a walk to load the bases. After Hader struck out David Villar, Pederson fouled off a 3-2 offering, then took the seventh pitch of the at-bat far outside, giving the Giants a ninth straight win.
Tyler Rogers (2-4), who stranded a pair of runners in a 3-3 tie in the top of the ninth, was credited with the win. The Padres, who got a home run from Fernando Tatis Jr, lost for the fourth time in six games.
Reds 8, Rockies 6
Elly De La Cruz homered and finished a triple shy of the cycle and Cincinnati held off a late rally from visiting Colorado for a 10th straight win.
TJ Friedl belted a go-ahead, three-run homer and finished with his first career four-hit game for the Reds, who matched their longest winning streak since July 2012. The Reds joined the Tampa Bay Rays (13) as the only major league teams with double-digit win streaks this season.
Nolan Jones homered, doubled twice and finished 4-for-4 for the Rockies, who dropped their seventh straight and 17th in 22 games while falling to 2-7 on their 10-game road trip.
Red Sox 10, Twins 4
Christian Arroyo homered among his career-high five hits and had four RBIs as Boston stretched its winning streak to six games with a blowout victory in Minneapolis.
Adam Duvall hit a solo homer and Masataka Yoshida went 3-for-5 with a two-run homer, three runs and three RBIs for Boston, which broke the game open with a five-run seventh inning. The Red Sox have outscored their opponents 50-18 during their winning streak.
Kutter Crawford (2-3) tossed five scoreless innings for his first victory since April 9. Corey Kluber pitched the final three innings for his first career save. Bailey Ober (4-4) took the loss, giving up three runs on eight hits over six innings.
Dodgers 2, Angels 0
The Los Angeles Dodgers scored two runs in the eighth inning to back seven shutout innings by Clayton Kershaw as they beat the Los Angeles Angels in Anaheim, Calif.
Kershaw and Angels starter Reid Detmers exited a scoreless game after seven innings, leaving the outcome to be decided by the bullpens. Michael Busch's bad-hop RBI single off Angels reliever Chris Devenski (3-2) in the eighth scored the first run. Will Smith added an RBI single later in the inning.
Kershaw (9-4) struck out five and allowed five hits and two walks. Evan Phillips pitched a 1-2-3 ninth for his eighth save. Detmers yielded two hits and a walk while fanning eight.
Cubs 4, Pirates 0
Tucker Barnhart and Mike Tauchman homered and Marcus Stroman pitched seven scoreless innings as visiting Chicago blanked Pittsburgh.
Stroman (9-4) gave up five hits, struck out five and walked one. Mark Leiter Jr. pitched a 1-2-3 eighth, and Adbert Alzolay did the same in the ninth. Pittsburgh starter Johan Oviedo (3-7) allowed two runs and five hits in six innings.
The Cubs are 9-2 in their past 11 games and have won five in a row against Pittsburgh, including a three-game sweep last week in Chicago. The Pirates have lost a season-worst eight in a row overall.
Astros 4, Mets 2
Framber Valdez carried a shutout into the eighth inning while Alex Bregman and Jose Altuve drove in two runs apiece as host Houston snapped a five-game losing skid by defeating New York.
Valdez (7-5) gave up two runs and completed eight innings. He allowed four hits and one walk and recorded nine strikeouts. Ryan Pressly earned his 13th save with a scoreless ninth.
Former Astros star Justin Verlander (2-4) took the loss in his return to Houston. He gave up four runs on eight hits in seven innings.
Braves 4, Phillies 2
Austin Riley and Matt Olson each hit a solo home run as Atlanta beat host Philadelphia.
Eddie Rosario added two hits and Ronald Acuna Jr. had two hits and an RBI for the Braves, who won their seventh game in a row. Spencer Strider (8-2) tossed six innings and gave up eight hits and one run with nine strikeouts and no walks. Raisel Iglesias allowed one run in the ninth inning yet still earned his 10th save.
Brandon Marsh had three hits while Bryce Harper, Kyle Schwarber and J.T. Realmuto each contributed two for the Phillies, who had their six-game winning streak snapped. Ranger Suarez allowed four hits and one run in six innings.
Blue Jays 2, Marlins 0
Ernie Clement broke a scoreless tie in the eighth inning by lofting a soft RBI single to center, helping Toronto beat host Miami.
George Springer also had a run-scoring single for the Blue Jays, who snapped a three-game skid. The Marlins had their five-game winning streak snapped. Former Marlins reliever Yimi Garcia (2-3) earned the win, and Jordan Romano picked up his 21st save of the season. Tanner Scott (4-2) took the loss,.
Miami's Luis Arraez, who started the day leading the majors with a .400 batting average, went 1-for-4. He is now batting .398.
Royals 1, Tigers 0
Daniel Lynch gave up only one hit in seven innings while recording his first victory of the season as Kansas City blanked host Detroit.
Lynch (1-3) walked two and struck out a pair while notching his first win since Aug. 1 of last season. Scott Barlow recorded his eighth save for the Royals, who won for just the third time in 18 games. Matt Beaty drove in the game's lone run with a double.
Detroit starter Michael Lorenzen (2-5) gave up one run and six hits in six innings. The Tigers threatened with a man on second and one out in the ninth, but pinch hitter Kerry Carpenter grounded to move the runner to third and pinch hitter Zach McKinstry struck out on a 3-2 slider.
Orioles 8, Rays 6
Aaron Hicks clubbed a three-run homer in the first inning as Baltimore scored four times, and the ORioles staved off a Tampa Bay rally to pick up a victory in St. Petersburg, Fla.
Hicks finished 2-for-4 and with four RBIs for Baltimore, which built a 7-0 lead through 4 1/2 innings. Anthony Santander went 2-for-5 with a homer and three RBIs. In five innings, Baltimore starter Kyle Bradish (3-3) yielded two runs on four hits.
The Rays' Isaac Paredes produced two singles, two runs and an RBI while reaching base four times, but Tampa Bay lost a third straight game for the first time this season.
Cardinals 9, Nationals 3
Dylan Carlson hit two home runs and Jordan Montgomery pitched seven strong innings as St. Louis ran its winning streak to four with a victory at Washington.
The Cardinals won for just the second time in the last 13 games started by Montgomery (4-7), who limited the Nationals to one run on four hits and one walk. He struck out six while matching his longest outing of the season.
Nationals starter MacKenzie Gore (3-6) worked six innings, giving up five runs on nine hits. Washington has lost nine of its last 10 games when Gore has pitched. The Nationals are on a five-game losing streak.
Yankees 3, Mariners 1
Gerrit Cole pitched 7 1/3 innings of one-run ball, Anthony Rizzo collected three hits and host New York beat Seattle to stop a four-game losing streak.
Cole (8-1) allowed four hits, struck out eight and walked one. Billy McKinney hit a two-run homer for the Yankees, who finished with eight hits.
Jarred Kelenic hit an RBI double for the Mariners. With several friends and family in the stands, Seattle starter George Kirby (6-6) allowed three runs on eight hits in seven innings. Kirby is a native of Rye, N.Y.
Guardians 3, A's 2 (10 innings)
Andres Gimenez lined a game-winning single with the bases loaded and no outs in the bottom of the 10th inning as Cleveland handed visiting Oakland its sixth straight loss.
Amed Rosario had three hits and Jose Ramirez had two for the Guardians, who won their second straight game. Enyel De Los Santos (3-1) pitched a perfect top of the 10th for the win.
Tony Kemp homered and scored two runs for the A's. Trevor May (2-4) took the loss.
Brewers 7, Diamondbacks 5
William Contreras' two-run double keyed a seventh-inning rally that gave Milwaukee a win over visiting Arizona.
The Brewers, who trailed 4-0 early, erased a 5-3 deficit with four runs in the seventh. Bryse Wilson (2-0) retired the only batter he faced in the seventh for the victory. Joel Payamps struck out three in the eighth, and Devin Williams finished for his 13th save in 14 opportunities.
Ketel Marte staked the Diamondbacks to a 4-0 lead in the second with a three-run homer off Colin Rea. Reliever Austin Adams (0-1) took the loss.
White Sox 7, Rangers 6
Zach Remillard singled home the go-ahead run in the eighth inning on a play overturned by replay review and Elvis Andrus had three RBIs to lift Chicago to a win against visiting Texas.
Eloy Jimenez and Andrus homered as Chicago avoided a fifth loss in six games and stopped the Rangers' winning streak at three. Corey Seager went 3-for-4 with five RBIs and Adolis Garcia belted a solo home run among his two hits to spark the Rangers.
The Texas bullpen couldn't uphold a 6-4 advantage, as Andrus contributed a game-tying, two-run single off Grant Anderson in the bottom half of the eighth to set the stage for Remillard.