In Saint Petersburg, Brazil scored twice in stoppage time to account for Costa Rica 2-0 and jump to the head of the Group E standings.

Philippe Coutinho poked the ball through the legs of Keylor Navas, who looked impregnable to that point, a minute into time added on before Neymar couldn't miss with what was the last meaningful kick of the game to seal the result.

Neymar was left in tears on the pitch post-match as the emotion of the occasion overwhelmed him.

"Neymar had a difficult injury, he went through a very hard patch," Coutinho said.

"His joy at being back on the pitch is contagious, everyone is so happy for him to come back, get on the pitch and score."

There was more late drama in the group's second game with Switzerland becoming the first team this tournament to come back from behind to win.

In a politically-charged match because of tensions with some Swiss players of ethnic Albanian heritage, Serbia took the lead but could not hold on and ultimately succumbed 2-1.

The Switzerland goals were scored by Granit Xhaka and Xherdan Shaqiri, both of whom are of Kosovo Albanian descent, and both celebrated by putting their hands together to make the symbol for Albania's double-headed eagle.

Furthermore, Serbian football association vice president Savo Milosevic was left to rue why the video assistant referee (VAR) was not consulted on a second-half penalty appeal for what he deemed was a foul in the box on striker Aleksandar Mitrovic, who had earlier given the Serbs a fifth-minute advantage.

"I understand maybe the referee didn't see it, but that's why we put VAR on. What are (those) guys doing up there?" Milosevic said.

The results leave Brazil, Switzerland (both four points) and Serbia (three points) fighting it out to advance from that section of the draw.

Nigeria joined Senegal as the only African teams to win so far in Russia with a comfortable 2-0 victory over Iceland.

The Super Eagles' superior pace in attack was critical with Ahmed Musa netting both second-half goals to put them on track to join Croatia as the teams to progress from Group D, although either Argentina or Iceland can spoil that scenario if results go their way next way.

Musa scored on 49 and 75 minutes, both brilliantly finished, before Gylfi Sigurdsson fired a penalty kick - awarded by the VAR - way over the crossbar in the 83rd minute to end any faint hopes of an Icelandic comeback.

After 26 matches in Russia there is yet to be a goalless affair although the 58 goals at an average of 2.23 per game is on pace to be the lowest scoring tournament.

The record low is 2.212 at the 1990 World Cup in Italy - a tournament seen as a low point for exciting games.

Australian Associated Press