MLB Power Rankings Week 4: New York Mets Reach The Pinnacle

Apr 26, 2015; Oakland, CA, USA; Houston Astros celebrate as they come off the field after defeating Oakland Athletics 7-6 at O.co Coliseum. Mandatory Credit: Bob Stanton-USA TODAY Sports

9. Houston Astros (11-7) Arguably the biggest surprise thus far this season, the Astros head into the fourth week of the season as the leaders in the AL West; they are actually the only team in that division with a record of .500 or better. Winning seven of their last eight games has helped that, including an impressive road trip to Seattle and Oakland, winning both series and sweeping the Athletics. All-star second baseman Jose Altuve continues to hit the baseball, registering 25 already, including eight multi-hit games and a streak of four consecutive.

8. Boston Red Sox (10-9) The Red Sox started the week off hot, winning two straight but had a rough finish to it. Back-to-back losses to end the series against the Rays was followed with a series loss to the Orioles. They lost in extra innings first, but then got crushed on Sunday afternoon, surrendering 18 runs. Hanley Ramirez and Pablo Sandoval have lived up to their expectations, as Ramirez is pacing the Red Sox in most offensive categories and Sandoval has the highest OBP.

7. Pittsburgh Pirates (11-8) The Pirates are one of the hottest teams in baseball right now, winning five games in a row. They have swept two of their last three series and Gerrit Cole is leading the way as the staff ace. What makes this even more surprising is that they are doing it with little help from perennial MVP candidate Andrew McCutchen. He is slashing only .186/.315/.322, but Gregory Polanco and Starling Marte have picked up the slack for him in the outfield.

Next: NL Powerhouses