The first trains are running on Melbourne's controversial 1.4-kilometre "sky rail", but passengers will have to wait until Thursday to experience it for themselves.

Test trains ran on a new stretch of elevated rail through Noble Park this weekend, as train drivers familiarised themselves with the first of three extended rail bridges the Andrews government is building to replace nine level crossings on the busy Cranbourne-Pakenham corridor.

The existing station at Noble Park is being demolished and an imposing new above-ground station will also open on Thursday, although it is still under construction.

Premier Daniel Andrews said he was proud to be able to say that the Corrigan Road, Heatherton Road and Chandler Road level crossings were gone forever.