This winter's No. 1 baseball drama (non-steroids division) took a giant step toward resolution yesterday when the Minnesota Twins agreed to send arguably the best starting pitcher in the majors to the New York Mets for four prospects.

News that Johan Santana was headed to the Mets, pending a physical and a contract extension - both should be slam dunks - had to have made the baseball ops people in Boston and the Bronx quite happy.

As much as the Red Sox and Yankees would have liked to have had the lefty, the biggest reason they entered the Santana sweepstakes was to play keep-away from each other.

"Whew" was the sound that came out of Fenway Park and Yankee Stadium when it was learned that Santana was Mets-bound.

The sound that came out of the executive offices at Citizens Bank Park was something closer to a deflating groan. The old "You sank my battleship!" commercial comes to mind here. One day after feeling pretty good about upgrading their third-base position with the signing of Pedro Feliz, the Phils were completely one-upped by their closest National League East rival.

The Mets added baseball's most precious commodity - a true No. 1 ace - while giving up nothing that figured to significantly impact their 2008 roster.

Despite their historic collapse of 2007, the one the Phillies (to their credit) capitalized on to win the division, the Mets remain a very solid club, one certainly capable of contending for the division in 2008. And that was before yesterday's big deal. Santana makes them better, more menacing in the Phillies' rearview mirror.

Check out some of the numbers on the guy who will call the NL East home for the next half-dozen seasons.

He'll be 29 in March. He won Cy Young Awards in 2004 and 2006. He finished third in the voting in 2005 and tied for fifth last season. Over the last five seasons, he has 82 wins, a 2.92 ERA and 1,152 strikeouts - all major- league bests over that span. And, of course, he's done that in the American League, where lineups are deeper and offenses are generally more potent.

Over his career, Santana has done his best pitching in the second half of the season. He is a remarkable 50-17 with a 2.79 ERA in 83 second-half starts in his career. After last season's collapse, the Mets have to feel good about adding someone like that.

Getting Santana takes pressure off the balance of the Mets' rotation: It moves Pedro Martinez, John Maine, Oliver Perez and Orlando Hernandez down. If the Mets can land Kyle Lohse or Livan Hernandez, they will become even deeper. Meanwhile in Philadelphia, the defending division champs could still use another good arm in their rotation.

Santana gives the Mets a stopper, like the Phillies have in Cole Hamels and the Braves have in John Smoltz. He alone won't win the NL East, but he betters the Mets' chances and certainly makes this a more interesting division. Before yesterday, we would have said the Phillies were the favorites to win the division. Now, Santana might give the Mets an edge.

Like Hamels, Santana's best pitch is his change-up. He'll throw a dozen sliders a game, but mostly, it's fastball-change-up. When he's on, and he usually is, he is a delight to watch - especially if he is on your team.

Mets fans are thrilled they will be able to watch Santana make 35 starts a year for the foreseeable future. Phillies fans could only dream of such a scenario. Once again, the Phillies did not have the prospects to enter the bidding for Santana. It was the same way when slugging third baseman Miguel Cabrera went from Florida to Detroit earlier this winter. How good would Cabrera's bat have looked in this ballpark?

It was no secret that Santana was going to be traded this winter. He was slated for free agency after the 2008 season and the Twins couldn't afford to re-sign him at numbers that could approach $20 million per season. The Twins put out the "for sale" sign and all the usual suspects put in their bids.

Time will tell who gets the best of this deal, but right now, you have to go with the Mets. Outfielder Carlos Gomez can fly, but there are questions about whether he'll hit in the majors. Deolis Guerra is a top pitching prospect, but he's a long way away. Kevin Mulvey and Phil Humber project as middle-to-bottom rotation guys. No one here was worth holding up a deal for a pitcher like Santana.

First-year Twins GM Bill Smith might have gotten more proven prospects (like the Yankees' Phil Hughes or the Red Sox' Jacoby Ellsbury) if he had made a deal sooner in the off-season. But he tried to increase his haul by playing tough, and in the end, with spring training two weeks away, the Mets' offer was the best one left.

So now, Johan Santana is headed to Queens. He will make the Mets better - and the Phillies' quest for back-to-back NL East titles a little more difficult.

Contact staff writer Jim Salisbury at 215-854-4983 or jsalisbury@phillynews.com.