It's going to be South vs. North in the final

To get the best perspective on this weekend's 2007 Rugby World Cup semifinals showdown, one needs to cast a quick look back at last weekend's quarterfinals matches, when we saw the unthinkable, the unimaginable, the untested and the unfazed.

The unthinkable was last Saturday's matinee matchup of Australia and England. While the Wallabies cruised into the knockout round, defending champion England came into the game as underdogs, having clawed through the pool round. After some early sparring and scoring exchanges, England never relinquished, sending the No. 2-ranked Wallabies packing with a 12-10 win.

Rugby fans still dazed from the afternoon game witnessed the unimaginable in the nightcap. The powerhouse All Blacks from New Zealand, the clear tournament favorite, blew a 13-3 halftime advantage on their way to losing 20-18 to France.

Sunday's knockout-round matches were relatively tame. The afternoon saw South Africa, practically untested after having blown through its pool rivals, cruise to a 37-20 victory over Fiji. In the nightcap, Argentina remained unfazed while holding off a charging Scotland to advance on a 19-13 win.

Regardless of the outcome of the semifinals, the 2007 RWC will come down to a final matchup between teams from the northern and southern hemispheres, just as it was in 2003 and 1999.
A breakdown of the semifinals matchups:

Saturday, Oct. 13
Match 1
England vs. France

This classic rivalry pits the defending RWC champs England against Les Bleus of France in a RWC semifinal rematch from 2003. Clearly, England is playing its most consistent rugby of the tourney while France has yet to let up in its quest for the Cup. Playing on home soil once again, France will have a slight fan advantage but look for England's fans to make their presence felt as well. This will prove to be one of the best games of the tournament.
Players to watch

Jonny Wilkinson, England: It's hard to look anywhere else but to the sure-footed fly-half Wilkinson, who's leading the team with 52 points.
Sebastien Cabal, France: France seems to rally whenever the fan-favorite "Caveman" takes to the pitch.

How they can win

England: With their new-found defense on a team finally playing as a whole, England needs to avoid costly penalties and not allow France to control the pace of play.
France: If Les Bleus throw the second-half attack they used against New Zealand and England, it will be a long and disappointing game for the defending champs.
Good to know: France has won four of the last five meetings with England.

Sunday, Oct. 14
Match 2
South Africa vs. Argentina
This clash of Southern Hemisphere titans will also see a battle of points leaders, with the Springboks' Percy Montgomery and his RWC-topping 76 points dueling with the Pumas' Felipe Contepomi and his team-leading 64 points. The Pumas are hoping to score an upset in their first semifinals appearance while the Springboks are now the favorite to hoist the Webb Ellis Cup.
Players to watch
Bryan Habana, South Africa: The speedster has six tries, second overall in the tournament.
Juan Martín Hernández, Argentina: He's managed to rack up four drop goals in the tournament.

How they can win
South Africa: Speed, speed, speed. The Springboks have it and use it to make the game look easy. That and a solid defense has them onto the finals.
Argentina: The Pumas have beaten the odds to get this far, thanks to their ability to adjust their play to their opponent's game. They'll need to control possession to deny the Springboks scoring chances.
Good to know: Dating back to 2000, Argentina has not beaten South Africa.

Peter Lion is an ESPN.com rugby contributor and director for "Outside The Lines."