4 big things to know from the weekend: The Astros are back but the Mariners aren't blinking

The dog days of summer are upon us. That time of year when the season seems never-ending, an eternal treadmill of 7:05 starts. But these games matter just like any others and the playoff picture, particularly in the National League, is shifting in real time. Clubs that have held firm spots for months are looking dinky, whereas slow starters have begun to surge.

Here’s everything significant that happened over the weekend.

The Houston Astros are back

Houston was 12 games under .500 on May 8.

Its pitching rotation was an infirmary. Stalwart third baseman Alex Bregman couldn't buy a hit. The expensive, highly vaunted bullpen was leaking runs like a styrofoam boat. Headlines like "Is the Astros' dynasty over?" flooded the timeline.

It appears rumors of their death may have been greatly exaggerated.

Houston is now seven games above .500, tied atop the AL West with the similarly surging Seattle Mariners.

The Astros stormed into historic Fenway Park over the weekend and rubbed their dirty shoes all over Boston's carpet, sweeping the Red Sox into the dustbin. Human battering ram Yordan Alvarez went 6-for-10 over the weekend with three long balls. Bregman, who has slowly picked his season up off the mat, added seven hits, four of the extra base variety. On Saturday, rookie hurler Spencer Arrighetti delivered the best start of his young career, sitting down 13 Sox across seven frames.

This team remains more flawed than its previous incarnations. The three-headed bullpen monster of Josh Hader, Bryan Abreu and Ryan Pressly has been more solid than dominant. First base remains something of a weak spot. Future Hall of Famer Justin Verlander, who made a rehab start Sunday, has been sidelined with a neck issue since June 9.

Still, this blue and orange monster under the bed, this boogeyman lurking in the shadows, looks set to make a run at its eighth straight ALCS appearance.

The Mariners aren’t rolling over

Seattle's rotation is so good, the type of group that can roll out of bed and win you a series if your lineup even shows up a little bit. In a home sweep of the Mets, Mariners starting pitchers combined to surrender just one measly run across 19 innings of work. The capper: a 12-1 bludgeoning on Sunday Night Baseball, the first time ESPN's prime-time game was in Seattle since June 6, 2004.

Franchise face Julio Rodríguez returned on Sunday from a high ankle sprain and went 0-for-5, but the rest of Seattle’s typically lethargic lineup stepped up. Catcher Cal Raleigh, who might be one of the most underrated position players in baseball, smashed a pair of homers. Second baseman Jorge Polanco added a long ball and two other hits. The Mariners sent Mets starter Luis Severino to an early shower before obliterating former Mariner Ryne Stanek for four runs in a third of an inning.

Seattle now embarks on a three-city, nine-game road trip with showdowns against the Tigers, Pirates and Dodgers.

The AL West race is heating up. And fortunately for the Mets, their two division mates in Philadelphia and Atlanta also had weekends to forget.

A crumbling for the ages at Coors

The snake-bit, injury-plagued Braves hobbled into Denver on Friday riding a five-game losing streak. More importantly, Atlanta sat on the outside of the NL wild-card picture for the first time all season. After dropping the opener at Coors Field, the Braves woke up on Saturday, scoring 11 runs in a cathartic victory. On Sunday, Atlanta carried an 8-2 lead into the eighth inning. The rainstorm appeared to be passing. Brighter days ahead.

Instead, the Braves' bullpen imploded, allowing seven runs in the penultimate frame to give Colorado an improbable 9-8 win. Anything is possible in the thin-aired wide expanse that is Coors Field, but this was a shocking show from Atlanta's bullpen. Because the Mets spent all weekend in Seattle playing with their food, Atlanta still has a half-game lead for the third NL wild-card spot. But with seven games left on a huge West Coast trip — San Francisco and Anaheim are next — the Braves are in danger of slipping even further.

NLCS redux

Arizona has the best record in baseball since the All-Star Break. Philadelphia has the worst record in baseball (non White Sox category) since the All-Star Break. The two teams met up in the desert for a four-game NLCS rematch. They were two teams destined for October baseball trending in opposite directions during the dog days of summer. And when the dust settled, Arizona had left little doubt.

After dropping the opener Thursday, the Diamondbacks spent the majority of the weekend obliterating Phillies pitching. They took Friday’s game on a walk-off homer by injury replacement catcher Adrian Del Castillo, before scoring 11 and 12 runs apiece on Saturday and Sunday against Philadelphia’s ballyhooed staff.

Arizona, who has a sparkling 17-5 record since the break, looks quite the formidable postseason opponent. Merrill Kelly and Eduardo Rodriguez, a pair of rotation linchpins, both returned from lengthy IL stints last week. Reigning NL Rookie of the Year Corbin Carroll has finally turned his season around. The Snakes are tied atop the wild-card ladder with San Diego, only 3.5 games adrift of the juggernaut Dodgers in the division. Chasing down L.A. is not completely out of the question.

Philadelphia, meanwhile, built up such a hefty division lead over the first half that a complete capitulation is extremely unlikely. The Phillies now head home after a lengthy West Coast swing during which they went 4-6. Things looked better during a key series win in L.A. against the Dodgers, but a lackluster showing in Phoenix puts these Phillies back under the microscope. There's still ample time to get things figured out.

A few other ones

The Dodgers swept the Pirates at Chavez Ravine, knocking around Paul Skenes for the worst start of his career on Saturday before a Tesocar Hernández's walk-off knock sent everybody home happy on Sunday. It was a huge win for the Dodgers who need to continue winning to keep the D-backs and Padres in the rearview mirror. Pittsburgh, meanwhile, has lost seven straight to drop them firmly out of the playoff picture.

The Orioles took two out of three against the Rays in Tampa, but couldn't pull off the sweep on Sunday. Most notably for Baltimore is the ascendency of rookie Jackson Holliday. The baby-faced infielder struggled mightily during a two-week stint in April, but has five home runs in 11 games since his recall on July 31.

The Yankees outlasted the Rangers in The Bronx to keep pace with Baltimore atop the AL East. Yankees deadline acquisition Jazz Chisholm Jr. blasted two more homers, giving him seven in 13 games since he was traded from Miami.

The surging Cubs took both games from the horrid White Sox and are now just three back in the wild-card race. If the Cubs could play every game the rest of the year against the SouthSiders, who have now lost three in a row after breaking their 21-game skid, life would be rosy.

The Twins took both ends of a doubleheader against the Guardians to claw within 1.5 games of their division rival, but Cleveland left Minnesota with a split to push its margin back to 3.5. Guardos closer Emmanuel Clase nailed down his league-leading 34th and 35th saves of the season.