A giant Chinese container ship has become the first vessel to move from the Atlantic to the Pacific Ocean via the newly-enlarged Panama Canal.
The ship was greeted with fireworks and cheers from a crowd that had gathered at the Cocoli locks to celebrate.
The Panamanian President, Juan Carlos Varela, described the waterway as a route that would unite the world.
The president thanked the nearly 30,000 people who had worked on the canal's expansion.
Construction on the new lane for the canal, which runs for 77km (48 miles), began in 2007 and was due to finish in 2014.
But strikes and disputes over costs delayed the $5.2bn (£3.8bn) project.
The original Panama Canal was first used in August 1914. It was built by the US and handed over to local control in 1999.
The expansion allows a new, much-larger generation of container ships to pass through the isthmus.
Some 35 to 40 vessels transit the waterway everyday.
Panama hopes the expansion will increase the revenues it gets from the canal, reported to have been $2.6bn (£1.9bn) in 2015.
But the canal could face competition from a new passage in Nicaragua.
The controversial 278km (172 mile) scheme, being built by a Chinese firm, will be longer, deeper and wider than the Panama Canal.
Its construction started in 2014 and it is estimated to cost $50bn (£32bn).