Barack Obama has won Maine's contest to choose a Democratic presidential candidate.
This hands rival Hillary Clinton another defeat in their tight race to represent the party in the November US election.
Yesterday's win made a clean sweep for Mr Obama of the states that have held nominating contests since Super Tuesday, when more than 20 states had their say in choosing candidates.
Mr Obama won Louisiana, Nebraska and Washington on Saturday, giving him a burst of momentum in a deadlocked race where every delegate to the party's summer convention has become crucial.
Maine in the north-east of the US is small in terms of the delegate votes it can send to the Democratic convention but when added to the three states carried by Mr Obama as well as the US Virgin Islands, this victory pushes him past Mrs Clinton in pledged delegates for the first time.
'I want to thank the people of Maine,' Mr Obama told a crowd of some 18,000 in Virginia Beach, saying he had won contests from coast-to-coast.
He was campaigning in Virginia ahead of its contest on Tuesday, when Washington DC and Maryland also hold elections.
Mr Obama is projected to pick up 15 delegates in Maine compared to nine for Mrs Clinton.
Mrs Clinton and Mr Obama have been almost even in pledged delegates but both are well short of the 2,025 needed to win the Democratic nomination.
When super delegates are counted, which are made up of senior members of the party, some news networks in the US are now giving Mr Obama a slight lead over Mrs Clinton.
Last night the Clinton campaign replaced its manager Patti Solis Doyle.
The campaign is reported to be playing down its ambitions for this week's contests.
Maine was contested by Republicans last week. Mike Huckabee's campaign is hoping for a victory in Virginia this week.
