The 16-year-old took the first set 6-0 against Juan Antonio Marin before the Costa Rican wildcard retired in the second with a knee injury.

BBC: Agassi powers through

Border tensions with Costa Rica about the San Juan river would have to be settled.

ECONOMIST: A man, a plan, a canal—Panama? | The

In 1848 the British invaded, renamed the port of San Juan as Greytown, and made a deal with Costa Ricans for use of the river.

ECONOMIST: A man, a plan, a canal—Panama? | The

Ms Lazzaris' problem stemmed from an error made by holiday giant Thomas Cook, where a member of staff had used the booking code for San Juan (SJU), Puerto Rico, instead of San Jose (SJO), capital of Costa Rica.

BBC: Right name, wrong place

And one of the many impediments to a long-mooted scheme to use the San Juan river for a second trans- ismithian canal is that it marks the frontier between Nicaragua and Costa Rica : efforts to patrol it frequently spark tension.

ECONOMIST: Border disputes

This week Nicaragua joined Costa Rica in asking it to help in their long-standing squabble over the use of the San Juan river.

ECONOMIST: Central America��s border order