SOCCER: PACHUCA USES OWN GOAL TO PUT CHIVAS IN A HOLE.

Byline: Daily News Staff and Wire Services

Guadalajara defender Hector Castro inadvertantly knocked the ball into his own net, and top-seeded Pachuca captured the first leg of a Mexican Primera Division Clausura semifinal Thursday night to head home for Sunday's finale with a 2-1 advantage.

Castro redirected Eduardo Rergis' cross in the 85th minute as the Tuzos rallied for the victory at Jalisco Stadium.

Jose Antonio Patlan, who made his Guadalajara debut April 29, fired Chivas ahead in the 50th minute, but Richard Nunez's third goal in as many playoff games pulled Pachuca even five minutes later.

Guadalajara, which last month surrendered seven starters to Mexico's World Cup preparations, overcame a one-goal deficit on the road to beat second-seeded Jaguares in the quarterfinals, also a two-game, total-goals series.

San Luis is home Saturday with a 2-1 lead over Toluca in the other semifinal.

--U.S. opens camp: The U.S. began preparations for the World Cup in Cary, N.C. The early focus is improving fitness, coach Bruce Arena said, and then ``building on our team concept.''

``We know all these players, and they know what we're about and how we do things,'' he said. ``It's just refining it and getting them back together and becoming a team again.''

--Elsewhere: Canada's MLS team, slated to begin play next season, will be called Toronto FC. ... The board at Italian giant Juventus resigned en masse following allegations of collusion in the appointment of referees for the club's games. Juve can clinch the Italian Serie A title Sunday.