Stephanie Houghton gave Great Britain Olympic lift-off in Cardiff this afternoon with the only goal in a 1-0 win against New Zealand.

In front of a 24,549-strong crowd, the 24-year-old curled home a superb second-half free-kick to give the home side a win that puts them on track for a place in the last eight of the 12-team competition.

The United States and Brazil also recorded wins on the opening day of competition at London 2012.

For England's Houghton it was fitting reward for the courage she showed to battle back from the disappointment of missing both the 2007 World Cup and 2009 European Championship through injury.

Even at last year's World Cup, her contribution was limited to just 39 minutes of the quarter-final defeat to France.

Watching from the stands, FIFA president Sepp Blatter must have been impressed at the cool manner of Houghton's finish, which secured a deserved win for Hope Powell's players, who take on Cameroon at the Millennium Stadium on Saturday.

Having complained so often at the lack of wider exposure her players have received down the years, Powell could hardly moan at the immense expectation that went with being the very first event of London 2012.

The enormity seemed to seep through though and, for 15 minutes, Team GB found themselves on the back foot against a New Zealand side that extended their hosts' defensive capabilities, with Hannah Wilkinson a particular danger.

That opening period was halfway through before Powell's side managed their first effort on goal, a curling Houghton free-kick which was pushed away by Jenny Bindon.

It was a foretaste of what was to come.

It was also the trigger for a more cohesive attacking display, with the supporters - large enough in number but swamped by the sheer size of the arena - right behind their team for all the debate about whether there should actually be a GB presence on the football pitch at these Games.

There was even a ripple of 'GB' around the stadium, although it came from the voices of school-age fans who will care little for the politics that overshadows a concept where reservations run deeper than Scottish duo Kim Little and Ifeoma Dieke opting not to sing God Save The Queen.

With Arsenal full-back Alex Scott starting to make her presence felt with regular forays forward from right-back, Great Britain began to get on top.

Scott failed to make the most of a decent chance after she had skipped into the box and Anita Asante was also off target with a couple of headers.

Asante went closest to breaking the deadlock with a move that took place almost in slow motion as Eniola Aluko's cross dropped to the far post.

There seemed little conviction in Asante's header. The direction was good though, with Bindon out of position and thankfully for New Zealand the post came to her rescue.

Great Britain continued to create chances following the introduction of Ellen White at half-time.

Jill Scott seemed to duck under Houghton's cross as Bindon somehow pushed it behind, then Scott had a goalbound effort blocked by Ali Riley.

When White lacked the pace to race away from the New Zealand defence, allowing Riley to block, it added to the hosts' frustrations and brought a fear their superiority was not going to be rewarded.

To the Cardiff crowd's delight, however, in the 64th minute Houghton kept her nerve with a 25-yard free-kick as she curled expertly into the bottom corner, with Bindon nowhere.

The cheers of delight were almost equalled by those of relief when a ridiculous mix-up between Scott and Dieke sent Sarah Gregorious clean through.

Gregorious panicked though, and rolled a pitiful attempt straight to Karen Bardsley.

The Linkoping goalkeeper was called on again nine minutes from time, when she tipped an Amber Hearn shot over.

GB were not to be denied though as they secured the win.

Alex Morgan scored twice as the United States produced a stunning comeback from two goals down to beat France 4-2 in their opening match of the Olympic Games.

The reigning Olympic champions looked in trouble at Glasgow's Hampden Park when Gaetane Thiney and Marie-Laure Delie handed France a 2-0 lead after 13 minutes.

However, Abby Wambach's header and a cool finish from Morgan brought the score level before half-time and further goals from Carli Lloyd and Morgan early in the second half gave the Americans a deserved victory.

Brazil went top of Group E as they opened their Olympic campaign in style with a comfortable 5-0 victory over tournament newcomers Cameroon at the Millennium Stadium.

Early goals from Francielle and Renato Costa put Brazil in control, before captain Marta with a brace and substitute Cristiane sealed victory.

The evening's other match was delayed when North Korea players left the pitch in protest after the South Korean flag was shown by mistake on the big screen as the they warmed up on the pitch prior to the match.

However, after a lengthy delay, North Korea returned and saw off Colombia 2-0.