When, in 1901, a Dutchman by the name of William Paats returned to Paraguay from Argentina with a ball beneath his arm, little did he know that he was about to sow the seeds of one of South America's longest-running rivalries.

And while few Cerro Porteno and Olimpia fans will be thinking about that moment when they assemble at the Estadio Defensores del Chaco on Sunday for the latest Asuncion clásico, the derby of the Paraguayan capital boasts a long and fascinating history, as FIFA.com reveals.

The origins
A PE teacher by profession, Paats organised Paraguay's first recorded football match, held at the Plaza de Armas in Asuncion on 23 November 1901. Although played largely by the country's affluent classes, the game spread rapidly and the following year a group of students formed the nation's first club. The founders considered naming the new institution Esparta or Paraguay but at Paats' behest they opted for Club Olimpia, which came into being on 25 July 1902.

Future rivals Cerro Porteno were founded just over a decade later on 1 October 1912, and owe their creation to a group of friends who played football in a modest neighbourhood near the Capilla San Juan. The club took its name from a battle fought in 1811 between the Paraguayan army and Los Porteñas (the forces of Buenos Aires) in the area around Cerro Mbae (Mbae Hill). The hill was later renamed Cerro Porteno in tribute to the resistance of the Paraguayan fighters, and the club's colours of blue and red symbolise the desire for unity between the various factions that habitually fought for control of the country.

The Paraguayan league began life in 1906 with Olimpia winning their first title in 1912. Cerro Porteno made their entry to the championship in style just a year later, winning the title without losing a single game. The first scheduled match between the two sides was cancelled when Olimpia failed to turn up, and there are various accounts of what happened when they finally did meet. According to some sources Cerro won 3-1, while others claim the game ended in a 2-2 draw. Whatever the result of that inaugural match was, the fact is that over the next six seasons Cerro won the league three times and Olimpia twice, marking the start of a fierce rivalry.

Facts and figures
Cerro Porteno have the edge in the 261 official league meetings between the two, winning 94 times to Olimpia's 89, while scoring 336 goals in the process, four fewer than El Decano. As Olimpia fans are always quick to point out, though, their side has won 38 league championships in all, nine more than their city rivals, not to mention three Copa Libertadores and an Intercontinental Cup, two trophies that have never graced their rival's trophy cabinet.

The top goalscorers in the fixture are Saturnino Arrua with 11 for Cerro and Mauro Caballero with 10 for Olimpia. The record for the most goals scored in one game is four, held jointly by Pedro Osorio and Dante, Osorio hitting his quadruple for El Ciclón in an 8-1 win in 1937, and Lopez matching the feat in a 4-1 Olimpia victory in 2005.

The two old adversaries are also evenly matched when it comes to unbeaten runs in the fixture. Cerro went ten games without defeat between 1992 and 1995, only for Olimpia to match that achievement between 2001 and 2004. Los Azulgranas hold the record for the most consecutive wins, however, stringing together five straight victories over Olimpia on two separate occasions, the first between 1986 and 1988, and the second between 2007 and 2008.

Tales of derbies past
1915 proved to be a memorable year in the history of the Asuncion derby, with four meetings in all. El Ciclón won the first 5-1, with Olimpia recording an even more emphatic 5-0 win in the second. A more sedate 1-1 draw followed before they met again in the league decider on 15 December. At the end of 90 minutes the sides were locked together at 3-3, with Cerro claiming the title with a four-goal burst in extra time.

The following year Olimpia gained revenge by dishing out a 10-1 hammering although the biggest victory in an official match between the two was that 8-1 win for Cerro in 1937.

There have also been some epic encounters in the Copa Libertadores, the first of them in January 1969. With the score locked at 1-1, Cerro forward Miguel Angel Sosa capped a fine solo run by rounding the goalkeeper and then sitting on the ball right on the goalline. After waiting for the keeper to get back to his feet, Sosa promptly stood up and rolled the ball over the line. The match, won 4-1 by El Ciclón, has gone down in history as El Clásico de la Burla (the Derby of the Taunt).

Olimpia got their revenge in the competition in 1991, when, as defending champions, they disposed of Cerro in the quarter-finals. Spurred by his dream of "knocking Olimpia then dying happily", Ramon Hicks gave Los Azulgranas a 1-0 win in the first leg. But Paraguay's oldest club easily turned the tie around in the second leg, winning 4-1 to advance to the semis.

In 1999 Apertura champions Olimpia took on Clausura counterparts Cerro in the national championship play-off. El Decano took the first leg 1-0 and in the return leg, billed as "the last clásico of the millennium" they overturned Cerro's 2-0 lead to win 3-2 and secure their third straight title.

Typically, El Ciclón would avenge that high-profile defeat. A point behind leaders Olimpia going into the penultimate game of the 2005 Clausura, they fought back from a goal down to run out 3-1 winners. A week later they were champions.

The rivalry today
That 2005 triumph was Cerro Porteno's last championship success, though Olimpia have endured an even longer barren spell, one that stretches back to 2000. Both are well placed in the current Apertura race, however. With five games to go Cerro stand top on 37 points and Olimpia lie third six points back. Sunday's encounter represents an opportunity for the leaders to pull away and a last chance for El Decano to keep their title hopes alive. With local pride also at stake after nearly a century of enmity, it should be quite an occasion.