The 54th-ranked Erakovic will now take on South African seventh seed, Channelle Scheepers, in the second round who has a current WTA ranking of 42.
They have played only once previously, with Scheepers taking that match in three sets in Rome earlier this year.
In the doubles draw, Erakovic had another long match as she and Brit Heather Watson took more than an hour to account for the unheralded American combination of Elizabeth Lumpking and Yasmin Schnack 6-2 2-6 10-8.
In the quarter-finals they will play Americans Jennifer Elie and Asia Muhammed.
When Erakovic and Watson last played together they won the title at Stanford.
The tournament is part of the build up for the US Open which commences next week in New York.