The Czech Republic rallied from a 2-0 deficit and were a man down in extra time before beating Japan on penalties on Wednesday and advancing to a quarter-final against Spain at the Under-20 World Cup.
Spain scored two extra-time goals to oust Brazil 4-2.
The US and Austria will meet in another quarter-final after tough wins in their second-round matches on Wednesday.
The Americans scored a last-gasp equalizer then beat Uruguay 2-1 in extra time, while Austria's Erwin Hoffer came off the bench to blast a late winner in their 2-1 win over 10-man Gambia in Edmonton.
Tomas Oklestek scored the decisive penalty for the Czechs after goalkeeper Radek Petr saved two in a 4-3 shoot out result after the scores were locked at 2-2 following extra time.
Japan opened the scoring in the 22nd minute when unmarked defender Tomoaki Makino headed home a corner and doubled the lead when Yasuhito Morishima converted a penalty two minutes into the second half.
Ondrej Kudela clawed one back for the Czechs in the 74th minute and then Jakub Mares converted from the spot three minutes later to send the game into extra time.
Despite being a man down when Mares was sent off for his second yellow card late in regulation time, the Czech Republic held on for 30 minutes to force the shoot out.
At Swangard Stadium, Leandro Lima gave Brazil the lead on 39 minutes with a spectacular scissors kick.
Alexandre Pato headed home Marcelo's pinpoint cross two minutes later to make it 2-0, but Gerard Pique reduced the margin almost immediately when he deflected Juan Manuel Mata's free kick into the goal.
Javi Garcia fired in a free kick six minutes from regulation time to equalize and then Alberto Bueno and Adrian Lopez scored in extra time as Brazil faded.
Another South American team lost in extra time when the US recovered to edge Uruguay.
Luis Suarez put Uruguay ahead in the 73rd minute, scoring on a rebound after Edinson Cavani's header was parried by diving American goalkeeper Brian Perk.
The US leveled with three minutes left when Danny Szetela's cross was deflected into his own net by Uruguay defender Mathias Cardaccio.
In the 107th minute, Uruguay 'keeper Yonatan Irrazabal failed to collect a corner and Michael Bradley scored.
The teams finished in Toronto shouting at each other and pointing fingers. Emotions ran high in a match which featured 57 fouls and eight yellow cards, five for the Americans.
Gambia's fortunes turned when midfielder Tijan Jaiteh was sent off for receiving his second yellow card for a foul on Veli Kavlak in the 43rd minute. Two minutes later, Austria scored when Kavlak's free kick was headed in by Sebastian Proedl.
Gambia deserved their equalizer in the 69th when Pierre Gomez scored.
Hoffer was brought on, chested Kavlak's pass and blasted the ball through goalkeeper Joseph Gomez's hands in the 71st.