Seager hit his career-high 31st homer in the seventh inning, lifting the Mariners to a 4-2 lead and helping them avoid a four-game series sweep at home.
“Getting his career high with 31 homers, it's something special,” teammate Marco Gonzales said. “I hope he plays for 10 more years.”
Perez nearly recorded another homer, lasering an RBI single off the top of the wall in right-center in the eighth. Nicky Lopez scored from first to cut Seattle's lead to 4-3, but Drew Steckenrider worked a perfect ninth for his seventh save.
Asked if he thought it was a home run off the bat, Perez smiled and said: “100 percent."
Perez’s solo shot off Gonzales (6-5) in the sixth was his fifth in five games. He started the series with grand slams in consecutive games, provided the deciding margin with a two-run homer Saturday, and then tied the game at 1 on Sunday.
The catcher matched Mike Sweeney’s team record of five consecutive games with a homer, set in 2002. The major league record for consecutive games with a homer is eight.
Perez also moved into a tie for fourth with Alex Gordon on the franchise list with 190 career homers, a former teammate who Perez said taught him a lot about being a professional.
“So I appreciate everything he did for us when he was here,” he said. “It's amazing, though.”
His 12 homers in August tied Chili Davis and John Mayberry for Kansas City’s most homers in a month.
Perez has 17 homers since the All-Star break, tied for the major league lead. Seager has 15 since the break, playing in every game.
“Kyle's been huge,” Mariners manager Scott Servais said. “And certainly after the All-Star break he's found that home-run swing, and we've needed it.”
Michael A. Taylor of Kansas City and Seattle’s Jarred Kelenic also went deep.
Gonzales pitched seven innings of five-hit ball to improve to 5-0 in his last 10 starts dating to July 9.
“He can really execute pitches when he gets on a roll,” Servais said. “The fastball truly was awesome, the way he located it.”
Perez is the first player to hit eight home runs on a road trip since Ryan Zimmerman in September 2013.
Servais took the unusual measure to make a mound visit in the eighth inning before Perez's at-bat so reliever Paul Sewald would be clear on his instructions.
“I will never forget that mound visit for as long as I manage the game,” Servais said. “Certainly he is the hottest hitter on the planet the last four days. ... I wanted to make sure we execute pitches. Paul assured me that he was not going to throw him anything he could hit. Unfortunately, we did not execute. And we were actually very fortunate that ball did hit the wall.”
Royals: LHP Richard Lovelady was placed on the 10-day injured list with a strained ligament in his left elbow. Manager Mike Matheny said Lovelady is scheduled for tests on Monday morning.
Mariners: CF Kyle Lewis (right meniscus surgery) could make a rehab appearance at Triple-A Tacoma on Monday or Tuesday after completing a workout in the outfield, Servais said. Servais met with Lewis recently to discuss the possibilities for the rest of the season, including a return to the lineup if his rehab assignment goes well. He’ll start out in a designated hitter role in Tacoma.
Royals: After an off day, Kansas City hosts Cleveland on Tuesday night in the opener of a three-game series. The Royals did not announced a starter. RHP Zach Plesac (8-4, 4.78 ERA) pitches for the Indians.
Mariners: RHP Chris Flexen (11-5, 3.54 ERA) starts Monday night in the opener of a three-game set against AL West-leading Houston. Seattle is 17-7 when Flexen starts.
Boston Red Sox offense 'the best we've been the whole season' in taking 2-1 ALCS lead, Alex Cora says
Red Sox manager Alex Cora cited preparation and communication for the dominant offensive numbers his team has been putting up in the ALCS against the Astros.
Red Sox pitcher Eduardo Rodriguez mimics Carlos Correa's watch gesture, drawing rebuke from Boston manager Alex Cora
After inducing a groundout by Carlos Correa, Red Sox pitcher Eduardo Rodriguez pointed to his wrist in reference to the Astros player's Game 1 celebration. The gesture drew a rebuke from Boston manager Alex Cora, but Correa thought it was "kind of cool."
Boston Red Sox make history as first team to hit three grand slams in postseason series
Grand slams by the Boston Red Sox during the regular season? Three. Grand slams by the Red Sox during the postseason? Three and counting.
MLB playoffs 2021 - Kyle Schwarber breaks open ALCS Game 3 and a brief history of October grand slams
Three swings in the past two games have netted Boston 12 runs. Here's how the feat stacks up to October's most epic bases-loaded long balls.
It's E-Rod's time: Eduardo Rodriguez mocks Carlos Correa's celebration in Game 3 win
A tale of two games. In Game 1, Houston Astros star Carlos Correa made sure Boston Red Sox pitcher Hansel Robles knew it was his time. In Game 3, Eduardo Rodriguez returned the gesture after getting Correa to ground out to end the top of the sixth inning.
Schwarber, Red Sox slam Astros 12-3, lead ALCS 2-1
— Red Sox starter Eduardo Rodríguez walked off the mound with a six-run lead and a message for Carlos Correa and the rest of the Houston Astros: