One conclusion that can be drawn from the first legs of the CONCACAF Champions League quarter-final ties is that the competition has never looked so wide open. Before the knockout-phase kicked off few would have imagined a Canadian side getting the better of a Mexican one or, for that matter, a Puerto Rican outfit seizing an advantage against a Honduran representative. Yet that is exactly what has happened.

All four ties are still too close to call after this week's exciting encounters, and with all eight teams still harbouring realistic hopes of reaching the semi-finals, there should be plenty more thrills in store in the return legs.

Perhaps the most eye-catching result was Montreal Impact's 2-0 defeat of Santos Laguna. The Canadians, who run out in the USL - the USA's second division - enjoyed the biggest night in their short history by securing a win that will live long in the memory.

To cap it all, the men from Montreal managed to attract a record crowd of 55,000, a huge figure for a sport that is some way from being the most popular in Canada. The fans were rewarded with a tactically astute performance from their heroes, who let their illustrious Mexican rivals control possession and then hit on the counter through the flamboyant Cuban-Panamanian strike duo of Eduardo Sebrango and Roberto Brown.

The Canadians were not the only contenders to punch above their weight. Puerto Rico Islanders kept their fine run going by defeating Honduran heavyweights Marathon 2-1 at a noisy Estadio Juan Ramon Loubriel. La Marea Naranja dominated the match from start to finish and were only prevented from recording a more comprehensive scoreline by some sloppy finishing.

The other two ties produced less surprising results. Houston Dynamo, Major League Soccer's last remaining representatives, were left to rue a late equaliser as they drew 1-1 at home to Mexico's Atlante. Dominic Kinnear's side have no option but to score when they travel to the Iron Colts' stronghold in Cancun in a week's time, but given the fact they have failed to win a single away game in the tournament, that might be beyond them. That said, the Mexicans did slip up at home to Trinidad and Tobago's Joe Public in the group phase.

All-Mexican clash
The week's other clash was an all-Mexican affair, with Cruz Azul continuing their recent dominance against Pumas UNAM with a 1-0 win at the Estadio Azul in Mexico City, a narrow result that did not do the young Auriazules justice.

Despite the absence of several first-teamers, Ricardo Ferreti's side held sway for most of the game but were undone by a smartly taken free kick from former Pumas youth product Jaime Lozano. The university outfit have now gone ten matches without beating their arch-rivals, a dismal run they will have to bring to an end at the Estadio Olimpico next Wednesday if they are to advance.

With so much still to play for, there should be plenty to entertain the fans when they line-up for the semi-finals of the CONCACAF Zone's blue-ribbon club competition is decided next week.