Bad defense and a lack of timely hitting doomed the Mets to a 5-4 walk-off loss to the Yankees (BoxScore).  The Yankees completed their 3-game sweep of the punchless Mets in the Bronx.  The Mets have now lost 6 of their last 7, and are now looking more like the last-place team everyone thought they would be.The Mets jumped out to a 3-0 lead in the second, on an RBI single by Vinny Rottino and a 2-run double by Jordany Valdespin.In the seventh, Andruw Jones reached on a throwing error by David Wright with 2 outs.  Russell Martin made him pay with a "home run" that bounced off the top of the right field fence, and into the hands of a fan who reached out over the field.  No word if his name was "Maier."  It was a Cheap Yankee Stadium Home Run (TM).  Don't ya know.There are a lot of similarities between Andy Pettitte and Jon Niese.  They're each left-handers who throw a fastball, cutter, curveball, and changeup, and they both have prodigious noses.  Today, they pitched similar games.Pettitte had one bad inning, the second, in which he allowed 3 runs, 2 earned, and struggled with his control.  But he cruised the rest of the way, baffling the Mets with his curveball, until he was lifted after 6 innings.Niese had one bad inning, the seventh, thanks mostly to Wright's error, and Yankee Stadium's little league dimensions.  The 2 runs were unearned.  Niese struck out 6 and walked 1 in 7 strong innings of work.With the Mets holding a 1-run lead after seven innings, the game came down the the bullpens.Bobby Parnell came in to pitch the eighth, and got Derek Jeter to tap weakly to short - a ball that promptly went right through Omar Quintanilla, allowing Jeter to go to second.  Three soft hits later, and the Yankees had tied the game.  Then Alex Rodriguez hit what would have been a routine popup to shallow right field, but since the infield was playing in, the ball dropped beyond the reach of Jordany Valdespin.  Not to make excuses for Parnell, but he didn't give up a hard hit all inning, and pitched into some bad luck.Tim Byrdak and Jon Rauch got the Mets out of the eighth without further damage.Lucas Duda led off the top of the ninth with a screaming double over the head of Curtis Granderson off of Rafael Soriano (BS, 1).  Ike Davis followed with a clutch RBI double to right-center field to tie the game at 4.  Omar Quintanilla showed bunt on the first two pitches that he saw, but then swung away and grounded to short.  Jayson Nix wheeled and threw to third and gunned down Ike Davis.  Should Davis have run?  The by-the-book rule is to run if the ball is hit at you or to your left.  To me, it looked like the ball was hit at Davis.  I don't necessarily fault him for going, but Nix executed his throw perfectly.  Have to give credit where credit is due.The next batter, Daniel Murphy singled to right, sending Quintanilla to third, but Boone Logan (W, 1-0) came in to strikeout Josh Thole, then got Kirk Nieuwenhuis to ground out to second.The Mets left the bases loaded in the second, and men on first and third in the ninth.  Two situations where they absolutely had to add on but couldn't - and they would regret it.Leading off the bottom of the ninth, Jon Rauch (3-6) threw one too many sliders to Martin, who hit another "home run" on a 3-2 pitch.The Mets continue their slog through the American League East as they begin a 3-game set against the Rays in Tampa on Tuesday at 7:10 PM EDT.