OAKLAND -- Matt Chapman is already proving to be a problem for any opposing pitcher, but something about seeing Marco Gonzales on the mound really gets him going.

Chapman has enjoyed more success against Gonzales than any other pitcher in his young career, and his reign of terror against the Mariners lefty continued on Tuesday night at the Coliseum with one of his most impressive performances of the year.

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Entering the day with a 9-for-20 line off Gonzales, the All-Star third baseman singlehandedly outscored the Mariners with a pair of two-run hits over his first three at-bats, including a two-run blast in the fifth inning off Gonzales to put the A’s ahead comfortably in a 9-2 victory and a fifth straight win.

“I’m just gonna call it dumb luck,” said the modest Chapman when asked what to make of his personal success against Gonzales.

Though Chapman has raked against Gonzales, the rest of the A’s lineup had come into the game struggling to get much going against the left-hander. Gonzales was 3-0 with a 2.57 ERA in his three previous outings against Oakland this season, and he retired the first seven batters he faced on Tuesday. But the A’s were finally able to break through with a two-run third after Chapman drove in his first two runs of the night with a single.

“Early on, we had a little trouble with him,” A’s manager Bob Melvin said. “Before, we had him on the run early in games and he’d get out of it and pitch deep. We finally got some balls to handle tonight.”

Gonzales has a deceptive ability to make pitches look like strikes until the last second, so the A's offense set out a plan to be more selective at the plate.

“For us, it was trying to hunt up and over the middle of the plate because he’s gotten a lot of early swings off of us, where we might think we see it good, but turns out it’s a ball or not the best pitch,” Chapman said. “He’s deceptive like that and has been pitching really well lately, but we were able to jump on him.”

Gonzales departed after six innings, but Chapman wasn’t done there, adding on to the lead in the seventh with an RBI double off Mariners reliever Matt Wisler to complete three legs of the cycle and finish 3-for-4 with five RBIs.

Though Chapman’s home run came on a 2-1 changeup down in the zone and was launched into the left-field bleachers, his hardest-hit ball actually came on his two-run single that was smoked into left in the third, which was also clocked as the highest exit velocity of any ball hit in the game at 111.6 mph, per Statcast.

Chapman continued his recent tear, now with 12 hits in his last 21 at-bats. Once considered a player whose biggest impact came on defense, he’s closing the gap on that theory, upping his batting average to .280 with 22 home runs and 59 RBIs for the season, leading the team in all three categories.

“It’s not a surprise,” Melvin said of Chapman’s hot streak. “He’s hitting homers, doubles, balls the other way, he’s really developed into a guy who knows what he can handle and when he gets it, he doesn’t miss. He just appears to be getting better and better.”

Strike-throwing machine

Daniel Mengden’s first five games up from Triple-A were uneven in terms of success, with the root of his issues coming from a lack of command that eventually led to a demotion. Since his return to the A's on June 26, the right-hander has tightened up that part of his game. He did not issue a walk on Tuesday for a third consecutive start and has only one free pass in his four outings back with Oakland.

“I’m not a big punchout guy,” said Mengen, who limited the Mariners to one run on four hits over seven innings. “I’m not going to blow guys away all the time, so it’s about staying aggressive and staying ahead. I’m always in the driver’s seat.”

Hottest team in baseball

It feels like deja vu for the A’s, who believe they have the makings of a second-half push similar to their 2018 run that ended with them earning a spot in the postseason as the second American League Wild Card team. They’ve won their first four games out of the All-Star break and are winners of 18 of their past 23 games, holding the best record in the Majors since June 17.

Oakland remains tied with Cleveland for the second AL Wild Card spot. After being 12 games back of first place in the AL West one month ago, the A’s now trail the Astros by 4 1/2 games, their closest margin since May 3.

“The divisional games are huge,” Chapman said of facing Seattle. “This is a team that has given us a lot of trouble. They always play us well and can really hit. To go down early and be able to come back and take the lead today was big.”

Teacher Appreciation Night at the Coliseum

The A's distributed nearly 5,000 complimentary tickets to Bay Area teachers and educators for Teacher Appreciation Night at the ballpark. The team hosted a pregame education fair, giving teachers the opportunity to learn about A's education partners and visit booths from community partners.