A portion of a transaction is received at a distributed transaction system from an initiator region. The distributed transaction system operates under a multi-tier two-phase commit protocol. A local unit of work is established that represents the portion of the transaction received from the initiator region. Processing of the local unit of work is invoked with at least one transaction participant. An indication is received from the initiator region to assume a role of transaction coordinator for the transaction. The initiator region is instructed to commit last relative to the at least one transaction participant of the local unit of work.