Although the attention of the football world is firmly focused on the Olympics this week, there will be plenty of club action to pique the interest of the dedicated football fan as well. While the race for top spot remains fierce in Japan, Russia and Brazil, Argentina's Apertura championship resumes, while hostilities will also commence in France.

Brasileirao: Blow for blow at the top
With two home wins in the last week, Gremio could be forgiven for expecting a solid buffer at the top of the Brasileirao. Not in the least. Hot on the Tricolor's heels are Palmeiras and Cruzeiro, both of whom picked up the full six points in the last two rounds as well. This weekend, Gremio face a tricky trip north to Belo Horizonte to take on Atletico Mineiro, yet another team coming off back-to-back wins. It must be some comfort for the leaders to know that their two closest challengers will also be playing away from home.

Big game: Flamengo have endured a nightmare run in recent weeks. Their early leadership of the Brasileirao is now a distant memory, and they desperately need a win at home to Atletico Paranaense, who are in danger of slipping into the drop zone, to keep in touch.
Player to watch: After a hat-trick on Sunday against Santos and another goal from the penalty spot in midweek, Coritiba's Keirrison may well extend his golden streak on Sunday at home to mid-table Sport Recife.

Japanese J-League: Top versus bottom
Only six points separate first from eighth in one of the most tightly-contested J-League seasons in recent memory. Kashima Antlers return from their week off to face bottom-of-the-table JEF United, and the Asian Champions league quarter-finalists will be buoyed by the memory of their earlier 4-1 thrashing of the Chiba side. Gamba Osaka, only three points off the pace, are also paired with a lowly side in Yokohama F Marinos, but a home loss to Oita Trinita in their last outing does not bode well for Akira Nishino's men.

Big game: Asian Champions Urawa Reds only trail Antlers by two points, but face a tough test at home to Kashiwa Reysol, themselves only five points in arrears, and 2-1 victors in the encounter between the same two teams in June.
Player to watch: Tatsuya Tanaka's late goal against the leaders on 27 July not only secured Urawa a precious point in the leadership race, but made him this season's top scorer. Can he keep his tally ticking over against Kashiwa?

Major League Soccer: Latin threat to Revolution
In the Eastern Conference, Steve Nicol's New England Revolution have been gradually pegged back, and face a tough test on Saturday against third-placed Chicago Fire, who finally concluded the sale of Olympics-bound Brian McBride to Toronto this week. For the Fire, talismanic Mexican attacker Cuauhtemoc Blanco returns after a one-game suspension, but Guatemalan youngster Marco Pappa impressed against Chivas as a replacement; will the two provide the Latin artistry to break open the solid Revolution defence?

Big game: DC United take the short trip up the Atlantic coast to face New York Red Bulls, with both sides fighting to stay in contention for the Conference semi-finals.
Player to watch: Colorado Rapids' Christian Gomez is getting better every week, according to his coach Fernando Clavijo, and will be fully recovered from his injury before long. Will his presence be enough to get Rapids over the line at home against Toronto FC?

Russian Premier League: Test of leaders' mettle
A series of draws at the top last weekend meant that Rubin Kazan held on to their slender 2-point lead, thanks to a last-minute equalizer from Turkish striker Gokdeniz Karadeniz against Energiya. The stage is now set for a barnstorming game between Kurban Berdyev's surprise leaders and UEFA Cup champions Zenit St. Petersburg, who have finally "caught up" with their postponed games. At the other end of the table, Shinnik are at home to Energiya in a classic relegation six-pointer.

Big game: Amkar Perm and Dinamo Moscow can both overtake Rubin with a win, so much will be at stake when second meets third at the Dynamo Stadium. The men from the capital won the first meeting between these sides 2-1 back in March, and Amkar have failed to score in their last three outings.
Player to watch: If Amkar have been wasteful in front of goal recently, spare a thought for CSKA Moscow, who have gone four games without a goal. Could Vagner Love, scorer of a hat-trick against Spartak in July, be the man to spark them back into life?

Two big leagues kick off this weekend, with the Argentinian Apertura resuming, and the French Ligue 1 clubs joining battle. In Argentina, champions River Plate face a difficult away trip to Colon on the opening day, while eternal rivals Boca Juniors, minus midfield maestro Juan Roman Riquelme, host Gimnasia Jujuy.

In France, champions Lyon kick off their seventh successive title defence on Sunday against Toulouse, who only just escaped the drop last season. Ambitious Marseille have a difficult first day at the office, away to Rennes, while the Girondins of Bordeaux will be welcoming Caen to the Stade Chaban Delmas. In a battle of fallen giants of the French game, Monaco host Paris Saint-Germain in the principality.