The United States remain in contention for a spot at next year's World Cup after Bruce Arena's side battled to a scrappy 1-1 away draw against Panama in CONCACAF qualifying on Tuesday.

A loss would have left the U.S. anchored equal bottom in the six-team group known as the Hexagonal, but the draw sends them home relieved and still in contention for one of the three automatic spots to Russia 2018.

Mexico extended their lead to three points atop the group with a 1-0 away win over Trinidad and Tobago, a second-half goal by Diego Reyes in Port of Spain lifting El Tri to 10 points from four games.

Costa Rica are second on seven points after a 1-1 away draw at Honduras, followed by Panama on five points, the U.S. and the Hondurans on four, while Trinidad have three points.

In Panama City, teenager Christian Pulisic set up striker Clint Dempsey for his 56th international goal as the U.S. took the lead in the 39th minute.

But Panama were on equal terms four minutes later when the American defence failed to deal with a long throw-in, the ball bobbling to Gabriel Gomez, who fired home from close range.

After the match, U.S. goalkeeper Tim Howard considered the result as one point gained rather than two points lost.

"We didn't tie the game, we won a dogfight," he said in a pitch-side interview. "It's tough away from home in qualifying. We had to get a point."

As for the physical nature of the contest, Howard did not mince his words.

"If you watch the game you would shake your head. It's what we've come to expect away from home with all the elements. We're always swimming upstream away from home.

"They're a physical team. This is probably the most athletic team in CONCACAF so it's hard to match them but I thought we did a good job."

Arena, who took over after the Americans lost the first two games of their qualifying campaign under Jurgen Klinsmann, was happy with the result, if not the officiating.

"The referee didn't blow his whistle too much," he said wryly, while conceding Mexico were now likely to win the group.

Mexico rode their luck against Trinidad, who felt aggrieved after a slick first half effort by Joevin Jones was disallowed for offside, though replays appeared to show he had timed his run to perfection.

The visitors had the better of the second half, with Hector Herrera hitting the post with a curling 20-yard shot, before defender Reyes powered home a header from a corner in the 58th minute.

"We knew it would be difficult... but in the second half we found the spaces and I think we deserved the victory in the end," defender Hector Moreno said.

In San Pedro Sula, Honduras bounced back from a 6-0 drubbing against the U.S. last week by sharing the spoils with Costa Rica.

Anthony Lozano bundled the ball home to give Honduras a first-half lead, before Costa Rica equalised in the second half with a Kendall Watson header.