The ongoing Olympic Games may be dominating sporting headlines across the globe, but the world's national football leagues are not giving up the limelight without a fight. Over in Brazil, the season will officially pass the halfway stage this weekend, though the eyes of many football fans will be drawn to the Seleção's quarter-final meeting with Cameroon in China PR. A similar story is unfolding in Argentina, whose men's Olympic side are also in the last eight with the country's Apertura set to move into its second week. brings you the lowdown on the best of the action outside Europe.

Argentinian Apertura: Jockeying for position
The six teams who emerged victorious on Matchday 1 (Arsenal, San Martin, Lanus, Rosario Central, Godoy Cruz and Tigre) will be aiming to take advantage of leaders Boca Juniors' postponed clash with Newell's Old Boys to knock Los Xeneizes off top spot, at least provisionally. Estudiantes and San Lorenzo, who both fell to opening-day losses, will be looking to kick-start their campaigns with all three points against Banfield and Godoy Cruz respectively.

The big match: Having picked up a hard-earned point from their trip to Colon, Clausura 2008 winners River Plate host a Rosario Central side who responded to their brush with relegation last season with an opening-day victory over Estudiantes. The previous meeting between the two sides ended in a thrilling 3-3 draw, while Rosario were the first team to defeat Diego Simeone's men last campaign. Making his debut for Los Millonarios could be Paraguayan sharp-shooter Santiago Salcedo. The former Newell's star would surely relish opening his River account against his old club's fiercest rivals.
Player to watch: Up-and-coming Estudiantes goal-getter Mauro Boselli is quickly growing into a Pincharratas' fans favourite. The former Boca man got off to a flyer with a brace against Rosario and another in the Copa Sudamericana, and he will look to continue this rich vein of form at the weekend.

Brasileirão: Clash of the titans in Porto Alegre
Though many football lovers may find themselves distracted by Ronaldinho and Co's attempts to reach the Olympic semi-finals, the Brasileirão action continues unabated, with Gremio currently flying five points clear of closest challengers Cruzeiro. The latter are set to take on fifth-placed Vitoria, one of the surprises of the season so far.

Flamengo, who at one stage held top spot for nine rounds, have slumped all the way down to seventh. Their opponents this weekend are struggling Santos, who are in the relegation zone at this, the halfway point of the season.

The big match: Leaders Gremio welcome fellow title aspirants Sao Paulo to Porto Alegre, where they remain unbeaten this campaign. Even the Paulistas' lethal forward Andre Lima could have his work cut out against a defence that has conceded just 12 goals so far, an average of just 0.6 per game.
Player to watch: Santos' 11-goal top scorer Kleber Pereira may share first place on the scorers' chart with Alex Mineiro of Palmeiras, but his club continue to toil away at the wrong end of table. "It's time to talk less and work more," said the player himself this week.

American Major League Soccer: Pistols at dawn for Western duo
It is first against second this weekend in the Western Conference, with Real Salt Lake looking to extend their one-point advantage over Houston Dynamo. New England Revolution and Chicago Fire, also separated by a single point, take on San Jose Earthquakes and DC United respectively.

The big match: New York Red Bulls, bottom of the Eastern Conference, take on a Toronto FC side above them only on goal difference. Victory would move either team back into play-off contention, and complicate their opponents' route to qualification.
Player to watch: Veteran USA forward Brian McBride, who played his last game in the Stars and Stripes shirt this Wednesday at Beijing 2008, has promised to be available for duty with Chicago Fire by Friday - thus putting himself in contention for this weekend's match. This despite having to endure an 18-hour plus flight back from the Far East.

Japanese J-League: Tight at the top
The four leading sides in the Japanese league all have theoretically straightforward fixtures this weekend, after a previous round of matches packed with surprise results. First-placed Kashima Antlers welcome mid-table Tokyo Verdy 1969, while Urawa Red Diamonds, just one point behind Antlers, travel to eighth-placed FC Tokyo. One point further back are Nagoya Grampus Eight and Kawasaki Frontale, who will cross swords with Vissel Kobe (9th) and Jubilo Iwata (14th) respectively.

The big match: After two consecutive defeats, Gamba Osaka travel to 12th-placed Omiya looking to get their title bid back on track. Gamba are three points off the top with eleven matchdays remaining, but Omiya have already served notice of their ability by winning the sides' previous meeting 3-2 in Osaka.
Player to watch: Masakatsu Sawa drew a line under his three-and-a-half year spell in Peruvian football to sign for Kashiwa Reysol in his homeland. Will the former Sporting Cristal, Coronel Bolognesi, Municipal and Cienciano man make his debut on Saturday against bottom side JEF United Chiba?

Much attention will no doubt be focused on the match between Pachuca and America in the Mexican Apertura competition, though the result itself will pale into insignificance. The game will likely be used to send a message of support to Águila star Carlos Sanchez, who suffered a stroke caused by a blood clot in his brain in training on Tuesday. and everyone involved in the beautiful game wish him a speedy recovery.

Gremio-Sao Paulo, Houston Dynamo-Real Salt Lake and Manchester United-Newcastle United are among the ten games featured in the opening round of FIFA's World League's Predictor. If you haven't yet signed up for free, then what are you waiting for? Simply click on the link to the right to join up and compete for some great prizes.