The collision happened 15 miles north east of Dover at 02:00 BST, the coastguard said.
The 183m (600ft) tanker Seafrontier, which is loaded with petrol, has a hole above the waterline and damage to the superstructure, the RNLI said.
The 225m (740ft) Huayang Endeavour was also damaged. None of the crew on board either ship was injured.
"Although both vessels have been damaged, there is no water ingress and no pollution," a coastguard spokesman said.
Huayang Endeavour was en route to Lagos in Nigeria and Seafrontier was travelling to Puerto Barrios in Guatemala. The vessels have Chinese and Indian crews on board, the UK coastguard said.
A tug from Boulogne was called and the Seafrontier was taken under tow. The Huayang Endeavour is anchored mid-Channel between the two shipping lanes.
Both ships are registered in Hong Kong.
Weather conditions at the time of the callout showed a moderate wind and the state of the sea was calm, the RNLI said.