Officers from Havant Fire Station were called to Petersfield Road, Havant, at 1.30pm when a mum called to say she was locked out.
The mum said her baby was locked inside the house.
Firefighters attended the scene for 10 minutes and got a chance to use their new break-in equipment.
A spokesperson for Hampshire Fire and Rescue said: ‘We were happy with the equipment. It proved effective and the door broke cleanly.’