The train arrived at the St Pancras International terminus at 11.48am after reaching speeds of more than 299kph on the new 109-kilometre high-speed link from the Kent coast.
Eurostar chief executive Richard Brown said: “The journey puts London and Brussels firmly within the two-hour club.”
The new link will shave 20 minutes off the time it takes to travel the 373km from Brussels to London when St Pancras opens to the public on November 14.
Eurostar has already set a record of two hours, three minutes and 39 seconds for the Paris to London run using the £5.8 billion (€8.28bn) High Speed 1 link, which is finally opening 13 years after the Channel Tunnel.
The new scheduled London to Paris service will take two hours and 15 minutes — 20 minutes faster than the present service to London Waterloo.
The 299kph top speed of Eurostar is 50% quicker than the fastest domestic British trains.
Mr Brown said: “The connections between domestic rail services and St Pancras International mean that travellers from across Britain will be able to reach Brussels, and cities throughout Belgium and France, in journey times that are competitive with flying, using trains that are more productive for business travellers, more relaxing for leisure travellers, and greener for all.”