Two of the strongest teams of the 2012 London Olympics men's football competition, World No. 1 Spain and Uruguay, have already been eliminated, and more upsets may be on the way as Korea faces tournament host Britain in the quarterfinals.

Also in the final eight are strong favorite Brazil, Egypt, Japan, Honduras, Mexico, and Senegal.

Brazil is on a roll, having won all three of its group games to finish top of Group C. It will meet Honduras, which finished second in Group D with seven points. Mexico, which racked up its second win by beating Switzerland 1-0 to lead Group B, will take on Senegal. Many experts predict Mexico will defeat the African side, but Senegal, which survived the so-called "Group of Death" with one win and two ties in Group A, will not be an easy foe. Its confidence will be shored up by having beaten Mexico 1-0 in a warm-up match before the Games.

Kim Hyun-sung volleys the ball over the bar during their men's football first round, Group B match against Gabon at Wembley Stadium during the London 2012 Olympic Games on early Thursday. /Reuters-Yonhap

Japan has already knocked out Spain, and it continues to ride its luck in the Olympic draw by avoiding host Britain and Brazil at this stage of the knockout rounds. Japan topped Group D after racking up a 1-0 win over Morocco in its final group game, and will play Egypt, which finished second in Group C with four points, for a spot in the semifinals. Although Egypt is considered one of the weakest teams in the final eight, its players also managed to squeeze two goals against powerhouse Brazil earlier in the competition.

The quarterfinals will get under way with Japan taking on Egypt at 8:00 p.m. on Saturday (Korean time), followed by Mexico vs. Senegal at 10:30 p.m. on the same day, Brazil vs. Honduras at 1 a.m. on Sunday, and Korea vs. Britain at 3:30 a.m. on Sunday.