Mexico 1-0 Germany
Defending champions Germany have made a disastrous start to their bid to win back-to-back World Cups, after losing their first match to Mexico on Monday morning (NZ time).
Hirving Lozano's first-half goal was the difference between the two sides in Moscow.
The highly-rated PSV Eindhoven forward struck the winner on 35 minutes, after a blistering counterattack at Luzhniki Stadium to beat Germany for just the second time in history.
It was also the first time a German side had lost their opening game of this tournament since 1982, when Algeria upset West Germany.
Germany had 67 percent possession and took 26 shots, compared to Mexico's 13.
Serbia 1-0 Costa Rica
Serbia captain Aleksandar Kolarov scored a spectacular free-kick in the second half to give his country a deserved win in their opening World Cup encounter match against Costa Rica.
Kolarov curled the ball the ball over the Costa Rica wall from nearly 30m out to score the match-winner.
"My players had the right attitude and approach - unity," Serbian coach Mladen Krstajic said after the game.
"We had to be a compact unit in both defence and attack, and that's most important.
"What's most important for me is that we played as a team and we were focused. We have to be planted firmly on the ground and continue as a team.
"I'm a person who likes to take responsibility, and even if we had lost, I would've come here to analyse the match to the best of my abilities. I'm pleased and proud of my players for their team effort."
Costa Rica's best chance at scoring came in the first half, when Giancarlo Gonzalez headed the ball over the crossbar.
Brazil 1-1 Switzerland
A second-half header from Steven Zuber cancelled out a sensational early goal from Philippe Coutinho, as Switzerland and Brazil drew 1-1 in a tight World Cup Group E
opener on Sunday (Monday NZ time).
Coutinho scored the game's opening goal to give the five-time world champions the lead.
But Switzerland fought back to tie things up five minutes into the second period, when Zuber rose unmarked to head home a corner kick.