Things remain tight at the top in Argentina, Mexico and Iran, where showdowns between several of the leading sides could have a major impact on the title races. By contrast, there is still a long way to go in the USA and Japan, where the early pacesetters are just beginning to emerge.

Argentinian Clausura: Chasing Lanus
Matchday 9 in Argentina features the battle of top and bottom, with the visit of Lanus to struggling Argentinos Juniors. With several sides breathing down their necks, Luis Zubeldia's Granate will be anxious to take all three points on their travels against a side that have yet to record a win.

Eager to pounce on any slip-up by the leaders will be the chasing pack, headed by Colon of Santa Fe just a point behind. Los Sabaleros welcome Arsenal to Sante Fe and will be mindful of the threat posed by their in-form striker Luciano Leguizamon. A point further back are Velez Sarsfield, who travel to Almagro to take on crisis club San Lorenzo. Elsewhere, Estudiantes and Boca Juniors, who both remain on course for a place in the knockout phase of the Copa Libertadores, cross swords with both hoping to put their early-season inconsistency behind them.

Big game: Taking centre stage this week is the meeting of River Plate and Gimnasia y Esgrima, two clubs with their share of ups and downs in recent campaigns. With both currently in the top six, a win for either side would keep them firmly in the race for this year's Clausura.
Player to watch: Can in-form Lanus striker Jose Sand maintain his goal-a-game average? After his master class in finishing last week, when he hit four of his side's five goals against Independiente, the competition's top-scorer made it eight strikes from eight outings.

Mexican Clausura: Pachuca-Toluca for top spot
Aside from the eagerly awaited meeting between the Tuzos and Diablos Rojos, there are several other eye-catching fixtures on Matchday 13 as the race for the play-offs hots up. One side who will monitoring events in Hidalgo closely are Pumas, who host Puebla, themselves riding high and with genuine play-off aspirations.

For their part, Jaguares will be hoping to strengthen their position and inflict more misery on Santos Laguna, who were denied a place in the final of the CONCACAF Champions League in midweek by compatriots Atlante. The latter will face Cruz Azul in an all-Mexican continental final, but for now the pair must turn their focus back to the domestic league, where they have found points hard to come by so far this campaign.

Big game: It is the most eagerly awaited match of the Clausura so far. Toluca, outright leaders and unbeaten this season, visit Pachuca, second in the general standings and only two points behind. The duel will not only bring together the country's most potent marksmen, but also pit current Pachuca supremo Enrique Meza against the club he led to three league titles between 1998 and 2000.
Players to watch: On this occasion that would be the Clausura's leading marksmen, who go head to head in the day's big game. In the Pachuca corner will be Argentinian Christian Gimenez, with nine goals to his name, while the visitors can boast the Chilean Hector Mancilla, on eight. Who will be ahead in the goalscoring charts come Saturday night?

J.League: Niigata on a high
The opening rounds have thrown up several big surprises, not least Albirex Niigata's ascent to top spot and the impressive start made by recently promoted Montedio Yamagata. With their strike duo of Brazilian Pedro Junior and Japan's Kisho Yano, who have already chalked up five goals between them, the leaders will be aiming to extend their unbeaten start away to Kyoto Purple Sanga.

Waiting to pounce any slip-ups by Albi will be second-placed Kashima Antlers, who travel to FC Tokyo in confident mood after comfortable win in midweek over Singapore Armed Forces in the AFC Champions League. Gamba Osaka, three points off the pace in third, face a tricky away fixture against Omiya Ardija, unbeaten with one win and three draws in their first four outings.

Big game: The meeting of Nagoya Grampus Eight and Urawa Red Diamonds brings together the teams in fifth and sixth respectively as they look to improve on mediocre starts to the season and edge closer to the summit.
Player to watch: Gamba Osaka's Brazilian Leandro has been finding his range in the group phase of the region's Champions League, netting four times in three games. Slightly less prolific on the home front with just two J1 goals this term, the front man and will be aiming to add to his tally this Sunday.

Elsewhere
Matchday 4 in the American Major League Soccer features the keenly contested derby that is Los Angeles Galaxy-Chivas USA. The visitors have three wins from three and are second in the Western Conference behind the only other team with 100 per cent record so far, Seattle Sounders. The latter, MLS newcomers, will be out to extend their perfect start when they welcome Kansas City Wizards to the Qwest Field this Saturday.

With just three rounds to play in the Iranian Pro League, Teheran side Esteghlal hold a one-point advantage over second-placed Zob-Ahan of Esfahan. Facing Foolad Khuzestan and bottom side Bargh respectively, both will be expecting three points to take the title race down to the wire.