Regional heavyweights Mexico and the United States both suffered defeats on Friday that put into doubt their chances of qualifying for next year's World Cup.
Mexico was beaten 2-1 at home by Honduras, dropping into fourth in the six-team CONCACAF group and outside the top three which qualify automatically for Brazil 2014. The fourth-placed team will go into a playoff against Oceania champion New Zealand.
The United States lost 3-1 at Costa Rica, which moved above the Americans into top spot with 14 points, one point ahead of the U.S. in second.
In Friday's other game, fifth-placed Paraguay was held to a 0-0 home draw by bottom team Jamaica.
Mexico took the lead in the fifth minute at the Estadio Azteca as Oribe Peralta netted a chance set up by Villarreal forward Giovani dos Santos.
However Honduras silenced the home fans with two goals in three minutes in the early stages of the second half.
Jerry Bengtson of New England Revolution equalized in the 63rd minute before defender Emilio Izaguirre teed up an opportunity for experienced striker Carlo Costly, who scored the go-ahead goal in the 66th. Honduras held on for a win that moved them above Mexico and into third place.
Costa Rica took the lead against the United States in just the second minute as Johnny Acosta headed in a Joel Campbell header.
Celso Borges made it 2-0 in similar fashion as he leapt high to head in a long cross by Christian Bolanos.
Clint Dempsey pulled a goal back with a firmly struck penalty in the 43rd minute but Campbell made it 3-1 to the Ticos as he got on the end of a Jose Miguel Cubero long ball, held off a defender and slotted home.
The next round of matches is on Tuesday, with the U.S. hosting Mexico in the key game while Honduras is at home against Panama and Costa Rica is away to Jamaica.