How can I set lead owner with api v2?

How can I set lead owner with api v2?

submitting 

"Owner":{
      "name":"owner name",
      "id":"owner id"
}

always leads to:

{"data":[{"code":"INVALID_DATA","details":{"api_name":"Owner"},"message":"invalid data","status":"error"}]}

whats wrong? And why do I need to submit the name?