Pablo Martinez Monsivais/Associated Press

The New York Yankees maintained their hold on the No. 1 spot in our weekly power rankings thanks to a big series win over the rival Boston Red Sox.

However, there was plenty of shuffling in the upper half of the rankings.

The Houston Astros continue to make their case for returning to the No. 1 overall spot, while there's still no clear-cut top team on the National League side of things. However, that could soon change, as the Washington Nationals finally seem to be hitting their stride after a disappointing first month.

At any rate, this remains a fluid process, as teams rise and fall based on where they were ranked the previous week. If a team keeps winning, it will keep climbing—it's as simple as that.

Here's an updated look at where all 30 teams stand heading into this week's action.

Updated Rankings 1 New York Yankees (28-12) 2 Boston Red Sox (28-12) 3 Houston Astros (26-16) 2 4 Los Angeles Angels (24-16) 5 Atlanta Braves (24-15) 2 6 Chicago Cubs (21-16) 2 7 Pittsburgh Pirates (23-17) 5 8 Washington Nationals (24-18)

10 9 Arizona D-backs (24-16)

6 10 Cleveland Indians (20-19)

1 11 St. Louis Cardinals (22-16) 5 12 Milwaukee Brewers (24-17) 2 13 Philadelphia Phillies (23-16) 6 14 Seattle Mariners (22-17) 1 15 New York Mets (19-18) 5 16 Toronto Blue Jays (21-20) 5 17 Colorado Rockies (22-19) 2 18 Minnesota Twins (17-19) 5 19 San Francisco Giants (20-21) 3 20 Oakland Athletics (19-21) 3 21 Cincinnati Reds (14-27) 8 22 Baltimore Orioles (13-28) 8 23 Los Angeles Dodgers (16-24) 2 24 Texas Rangers (16-26) 25 Tampa Bay Rays (16-22) 5 26 San Diego Padres (16-26) 1 27 Detroit Tigers (17-22) 28 Miami Marlins (14-26) 6 29 Kansas City Royals (13-27) 3 30 Chicago White Sox (10-27) 2

Teams That Impressed

Derik Hamilton/Associated Press

After a four-game sweep of the Arizona Diamondbacks—the No. 3-ranked club and top overall NL squad in last week's rankings—the Washington Nationals are finally starting to look like the team everyone expected them to be when the season began.

An 11-16 start saw them tumble to the bottom half of the rankings, but they've since gone 13-2.

The starting rotation boasts an NL-best 2.91 ERA, and minor league free-agent signing Jeremy Hellickson (6 GS, 1-0, 2.20 ERA, 0.86 WHIP, 32.2 IP) has been a pleasant surprise filling the No. 5 starter role.

The Philadelphia Phillies also move into the upper half of the rankings on the strength of a four-game sweep of the San Francisco Giants.

A 14-7 start was followed by a 3-7 stretch of games, but they're back on the rise at 6-2 in their last eight.

Odubel Herrera (158 PA, .360/.430/.561) leads the NL in batting average, while Aaron Nola (9 GS, 6-1, 1.99 ERA, 0.99 WHIP) has continued his ascent as one of the game's best young pitchers.

The Pittsburg Pirates and Minnesota Twins both climbed five spots in this week's rankings, continuing what has been up-and-down seasons for both clubs.

The Pirates have exceeded expectations after it appeared they were headed for a rebuild, as they sit a half-game back in the NL Central standings. Meanwhile, the Twins stumbled to a 9-16 start on the heels of last year's Wild Card Game appearance, but they've now gone 8-3 in their last 11.

Finally, the two teams ranked at the bottom last week—the Cincinnati Reds and Baltimore Orioles—each moved up eight places after a pair of impressive weeks.

The Reds took two of three from the New York Mets and then swept four games from a struggling Los Angeles Dodgers team.

As for the Orioles, they scored series wins over the Kansas City Royals and Tampa Bay Rays—just the third and fourth times this season they've come out on top in a series.

Teams That Disappointed

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What's wrong with the Los Angeles Dodgers?

The short answer is a lot.

Injuries have hit hard as Clayton Kershaw, Justin Turner and Corey Seager have all missed significant time. The bullpen has been a disaster with a 4.51 ERA that ranks 22nd in the majors and 10 blown saves in 17 chances. The offense has been largely mediocre in averaging 4.3 runs per game and hitting .239 as a team.

They don't look like the same team that has rattled off four straight NL West titles and came one win away from a World Series title a year ago.

Take away a 7-1 stretch of games in the middle of April, and they've gone 9-23 the rest of the way.

A three-game sweep at the hands of the Nationals costs the Arizona Diamondbacks six spots in the rankings, as they came up short in a big test to prove they were the top team in the NL.

With Taijuan Walker out for the season and Robbie Ray also on the DL, they've been forced to scramble a bit to round out the starting staff. To his credit, Matt Koch (6 G, 5 GS, 2-1, 2.43 ERA, 33.1 IP) has more than held his own.

The New York Mets and Toronto Blue Jays continued their downward trend after impressive starts to the year.

The Mets exploded out of the gates to an 11-1 start, but they've since gone a dismal 8-17 with a minus-39 run differential in their last 25 games.

As for the Blue Jays, they went 12-5 to begin the year, leaving them three games back in a tightly contested AL East division on April 18.

They're just 9-15 with a minus-33 run differential in the 24 games since.

It was a rough week for the Bay Area, as the Oakland Athletics and San Francisco Giants both dropped a pair of series and went a combined 2-11.

Likewise, the Tampa Bay Rays, Miami Marlins and Chicago White Sox also won just one game each in last week's action, though the White Sox were able to finally raise their season win total to double digits with a win over the rival Chicago Cubs on Sunday.

MVPs of the Week

Hitter: Willson Contreras, Chicago Cubs

Stats: 11-for-23, 3 2B, 2 3B, 3 HR, 12 RBI, 6 R

Coming out of the All-Star break last season, Cubs catcher Willson Contreras was arguably the hottest hitter in baseball.

Over the first 23 games of the second half, he hit .311/.380/.700 with 10 home runs and 29 RBI, before a hamstring injury abruptly sidelined him for a month.

Why is that relevant now?

The 26-year-old is on a similar tear for a Cubs team that finally seems to be finding some momentum, despite an inconsistent starting rotation.

Kris Bryant and Anthony Rizzo might be the two superstars on the roster, but no single player is more critical to success on the North Side than the young catcher who has been absolutely raking.

Pitcher: James Paxton, Seattle Mariners

Stats: 2 GS, 1-0, 15.0 IP, 6 H, 3 ER, 3 BB, 11 K

When James Paxton took the ball last Tuesday night, he probably wasn't expecting to top his previous start.

On May 2, he struck out a career-high 16 batters over seven scoreless innings against the Oakland Athletics, lowering his ERA nearly a full run in the process.

While he didn't match that gaudy strikeout total, what he did do was secure a spot in the record books, tossing the sixth no-hitter in Seattle Mariners history. He needed just 99 pitches and a couple of defensive gems to blank the Blue Jays in Toronto.

Here's a look at the other five hurlers who have tossed a no-no in a Mariners jersey:

6/2/1990: Randy Johnson

Randy Johnson 4/22/1993: Chris Bosio

Chris Bosio 6/8/2012: Kevin Millwood (6 IP), Charlie Furbush, Stephen Pryor, Lucas Luetge, Brandon League, Tom Wilhelmsen

Kevin Millwood (6 IP), Charlie Furbush, Stephen Pryor, Lucas Luetge, Brandon League, Tom Wilhelmsen 8/15/2012: Felix Hernandez

Felix Hernandez 8/12/2015: Hisashi Iwakuma

After pitching to an ugly 5.61 ERA in his first five starts, Paxton once again looks like the budding ace we saw when he was healthy last season. He followed up his no-hitter with six strong innings in a no-decision Sunday.

Video Highlights of the Week

Longest Home Run: George Springer, Houston Astros (462 feet)

George Springer is no stranger to long home runs.

He counted a 473-footer among his career-high 34 long balls last season, and he was at it again this past week, launching a 462-foot bomb off veteran left-hander Brett Anderson.

That wasn't the only damage Springer did in that game.

The 28-year-old went 6-for-6 in what wound up being a blowout 16-2 victory over Oakland.

That was enough to elicit a bow from teammate Jose Altuve, a man who knows a thing or two about racking up hits after leading the AL in that category each of the past four seasons.

Best Defensive Play: Kyle Seager, Seattle Mariners

Defensive play of the week choices won't come any easier than this one.

This diving stop from Mariners third baseman Kyle Seager with two outs in the seventh inning preserved a no-hitter for James Paxton—who went on to finish off the historic feat.

With the fleet-footed Kevin Pillar busting it down the line, Seager had to get off a quick, accurate throw with little margin for error, and he put it right on the money.

The 2014 AL Gold Glove winner remains among the more underrated players in the game, as he's quietly been one of the league's best two-way third basemen for a number of years.

Must-See Upcoming Matchup

Chicago Cubs vs. Atlanta Braves (Monday-Thursday)

Michael Reaves/Getty Images

When the Atlanta Braves started rebuilding from the ground up a few years ago, the Chicago Cubs' own rebuild a few years prior no doubt served as a blueprint of sorts.

Now, the Braves appear ready to contend once again with a 24-15 start that has them all the way up to the No. 5 spot in these rankings after they checked in at No. 22 on Opening Day.

Meanwhile, the Cubs shook off a five-game losing streak to go 5-1 last week, sweeping the Miami Marlins before taking two of three from the crosstown-rival Chicago White Sox.

While those are two of the league's worst teams, the Crosstown Classic is always a hard-fought series, and the weekend should provide some momentum going forward.

This series will actually begin with a makeup game in Chicago on Monday before the teams travel to Atlanta for the originally scheduled three-game series.

If nothing else, this will be a showcase of some of the best young talent the NL has to offer.

All stats courtesy of Baseball Reference and FanGraphs unless otherwise noted.