Narrow wins for Mexico and the United States Wednesday hugely strengthened their chances of reaching next year's World Cup Finals while Costa Rica suffered a surprise defeat to El Salvador. Ricardo Clark struck a 62nd minute goal as the United States labored to a 1-0 win away to Trinidad and Tobago while Mexico needed a 75th minute Cuauhtemoc Blanco penalty - and some late luck - to beat battling Honduras by a single goal at the Azteca Stadium. El Salvador kept alive its slim hopes of qualifying with an injury time goal from Rudis Corrales that condemned Costa Rica to a 1-0 loss – its second straight defeat. The results mean that the United States leads the group on 16 points with Mexico second on 15, followed by Honduras (13), Costa Rica (12) and El Salvador (8) with two rounds remaining. Trinidad's defeat leaves them bottom of the six-team group on five points and formally out of qualifying contention. The top three teams automatically qualify for next year's Finals in South Africa while the fourth-placed team must playoff with the fifth-placed side from South America. Only some surprising outcomes will stop the US and Mexico from taking two of those automatic spots even though neither side would be entirely satisfied with their performances Wednesday. The US survived some scares during a scrappy first half - most notably when Cornell Glen struck the cross-bar with a lob in the 29th minute. Jozy Altidore responded with a fierce strike from distance which Trinidad keeper Clayton Ince did well to keep out. But the home side continued to press forward and Trent Noel twice went close with free-kicks just before the interval. The US, which had lacked fluency and purpose in a ragged first half display, produced a sterner performance after the interval and grabbed the lead with Clark's powerful strike from 20 meters out. Coach Bob Bradley looked ready to substitute Clark moments before he picked up the ball from Landon Donovan and unleashed his superb shot. Mexico totally dominated the first half against a cautious Honduran team but were unable to convert their chances - Miguel Sabah missing two good opportunities just before the break. Honduras keeper Noel Valladares also frustrated El Tri as he produced a great save to keep out a blistering drive from Efrain Juarez that was rocketing into the top corner and another to foil Guillermo Franco in the 30th. But the breakthrough came when winger Giovani Dos Santos went down after push in the back from Maynor Figueroa and Blanco converted with ease. Honduras then piled on the pressure in the final stages - Mexico keeper Guillermo Ochoa saving at the near post from Julio De Leon in the 86th minute and then Carlos Pavon headed over from a promising position in injury time. The win extends Mexico's unbeaten run to 12 games. Cameroon jumps to the top Cameroon beat Gabon 2-1 in Yaounde in a World Cup qualifier Wednesday to move to the top of Group A. Cameroon tops the group with seven points from four games, while Gabon is second with six points. The match was initially scheduled to be played June 20 but was postponed after the death of Gabon's leader Omar Bongo Ondimba, who had ruled the country for 41 years.