A passenger-carrying train has arrived at Waterloo's platform 20 for the first time in more than 5 years.
A passenger train has used an international platform at Waterloo station for the first time since the last Eurostar service left more than five years ago.
In 2008 the Government spent nearly £3 million connecting platform 20 in the international terminal with platform 19 on the domestic side, but no trains have used the new facilities until now.
The special VIP service from Woking pulled into platform 20 on Monday as rail bosses confirmed the platform will be brought into regular use by April 2014.
The journey into the Waterloo International Terminal was made to mark the first anniversary of the Network Rail and South West Trains Alliance.
Tim Shoveller, managing director of the Network Rail and South West Trains Alliance, said: "The alliance is an industry first which was created to deliver a better railway for passengers using ways of working which have not previously been possible.
"Bringing the Waterloo International Terminal into permanent use is an example of what it can help to achieve.
"It has been made possible by working with many organisations, including the Department for Transport, and is vital for the much-needed development of the railway across the south and south west of England.
"It has been talked about for many years and we have shown it is possible and remain committed to bringing platform 20 into permanent use by April 2014 at the latest."
However, there is no firm timetable as yet for reopening platforms 21, 22, 23 and 24 at Waterloo. The alliance says that it will continue to work with the Department for Transport to develop plans for the whole of the international terminal to be used and other platforms to be extended.
Passenger numbers at Waterloo are predicted to grow by 51 per cent over the next 11 years.