The cardboard cutout drawing of a moving van wasn't winning any design contests, but the crude creation served its purpose as it crowd surfed the River End of PPL Park, passed along from hand to hand, a masterpiece of trash talk floating in a sea of contempt.

The Sons of Ben, the Philadelphia Union supporters group, were the creators of the harsh reminder to D.C. United fans that their team doesn't have a permanent home, and just might leave D.C. one day. It was the kind of stinging message that had to make the hundred or so D.C. United fans seated just a few yards away from the Sons of Ben cringe, but also crack a smile of appreciation because scenes like those, and games like the five-goal thriller taking place on the PPL Park field are what rivalries are all about.

In the pecking order of MLS rivalries, Union/D.C. United isn't quite on par with the likes of Portland/Seattle, D.C./New York, Columbus/Toronto FC, RSL/Colorado or LA/Chivas USA, each boasting its share of historical hatred and memorable moments to stir the emotions of fans and players alike. Union/D.C. United doesn't have the history of those other established rivalries, but it has the potential to eventually be as good a rivalry as there is in the league.

Philadelphia' 3-2 victory over D.C. United not only helped push the Union to second place in the East in the thick of the playoff race, it also gave the Union bragging rights against their more-established rival.

Sebastien Le Toux (R) of the Philadelphia Union tries to head the ball on goal while being defended by Brandon McDonald (L) of D.C. United. (Photo by Drew Hallowell/Getty Images)

"It brings just an added intensity, especially at this time of year, with such a close race," Union midfielder and former D.C. United player Brian Carroll said of having two closely located teams forge a budding feud. "It's a rivalry that's growing and it's going to get more and more intense as the years go by."

"You have the close proximity, and you have storylines like Peter (Nowak) having been D.C. coach and me being raised in Philly from a soccer standpoint, but what a rivalry needs is big games," said D.C. United head coach Ben Olsen. "You need those championship games, those playoff games, that people remember and that help build the kind of animosity every good rivalry has."

The 120 miles between D.C. and Philadelphia would be a long distance for a rivalry to form by European standards, but in the United States, the two cities may as well be neighbors. That proximity surely plays some part in the interwoven links between the clubs. Union head coach Peter Nowak coached D.C. United to the 2004 MLS Cup, along with current Union midfielders Brian Carroll and Freddy Adu, as well as Union staffers Alecko Eskandarian.

Then there are the links between the fan bases. There are a good number of Union fans who once called D.C. United their favorite team, back when MLS in Philadelphia seemed like a pipe dream and D.C. United was dominating the league. Once the Union were born, however, many of the Philly locals who had aligned themselves with D.C. quickly traded in their black and red for blue and gold, a fact that surely adds some spice to the contempt between the fan bases.

Michael Farfan #21 of the Philadelphia Union heads the ball in front of Clyde Simms #19 and Perry Kitchen #23 of D.C. United. (Photo by Drew Hallowell/Getty Images)

As much as fans will play a major part in providing spice to the rivalry, and Philly and D.C. happen to boast two of the most passionate fan bases in MLS, how far the rivalry goes will ultimately be determined by the players, which is another reason to have such high hopes for the Union/D.C. United feud.

You'll have a hard time finding two teams with better collections of young talent in MLS than Philadelphia and D.C. United. The Union features the likes of Freddy Adu, Danny Mwanga, Michael and Gabriel Farfan, Zac MacMath and Roger Torres. D.C. boasts a nucleus of young standouts including Andy Najar, Bill Hamid, Chris Pontius, Perry Kitchen and Ethan White.

It will be those young stars who help make Philadelphia and D.C. United league powers in the coming years, and it will be those same players who play key roles in writing new chapters in the Union/D.C. rivalry. Chapters that will eventually include playoff battles, fights and enough unforgettable nights to make both team's fans feel an extra sense of urgency when they see the other team coming up on the schedule.

"Being involved with those kind of rivalries, like you see in the rest of the world, isn't just special for fans, it's a great experience for players," said D.C. United forward Josh Wolff. "You saw tonight the atmosphere, and the soccer-specific stadium, and the fact it was on (national) television, two good teams playing an exciting game. Nights like these help build a rivalry."

When will the Union-D.C. United derby be seen as the best or one of the best in MLS? That day will come sooner rather than later, and one day nights like Thursday night at PPL Park will be considered tame by comparison, the humble beginnings of a truly world-class rivalry.