Air New Zealand Flight NZ974 from Auckland has just landed in Tonga after an earlier flight today had to turn back, the company says.
It follows days of disruption to international and domestic flights caused by ash from the Hunga-Ha'apai offshore volcano.
The ash cloud has stranded hundreds of holiday-makers, and some of the backlog of cargo is starting to spoil.
Viliami Ma'ake, the chief executive of Tonga's airport, said cargo like fish had not been able to be sent overseas.
But he said the ash cloud was not affecting high-flying aircraft passing above Tonga on their way to other countries.
Virgin Australia also managed to land a plane from Sydney in the capital Nuku'alofa this afternoon and has also managed to return from there to Auckland.
Immigration New Zealand said it had managed to meet and assess all of the passengers stranded at Auckland Airport while trying to make it to Tonga.
About 24 passengers were effectively stuck in transit today after being on the earlier flight that had to turn back because of ash from Hunga-Ha'apai.
Where possible, passengers were allowed entry back into New Zealand.
An Immigration New Zealand spokesperson said some of the stranded passengers left on the Air New Zealand flight that has just landed in Nuku'alofa.
Flight NZ974 is the first Air New Zealand flight that has been able to land in Tonga since the latest volcanic disruption forced flights to be cancelled.
Facts about the Hunga Ha'apai volcano
- It is an ocean volcano that is about 62km from the main island, Tongatapu
- It has regularly been erupting for decades
- The volcano last erupted in 2009, forming an island
- Just after Christmas last year, it resumed activity and GNS said it appeared to be forming a larger island at present
Why ash is a danger for air travel
- Volcanic ash melts inside a hot engine
- Ash also conducts electricity when it is wet so there is a possibility of shorting out electronics
- A build-up of ash in the engine can cause it to stall and shutdown
- Science Media Centre