World number seven Eugenie Bouchard's struggles in 2015 continued on Saturday as qualifier Tatjana Maria dumped her out of the Miami Open in straight sets.

Having suffered defeat to Lesia Tsurenko at Indian Wells a fortnight ago, Bouchard tumbled out of her second straight WTA Premier event to a qualifier, as world number 113 Maria secured a 6-0 7-6 (7-4) success.

The 21-year-old Canadian committed four double faults in a first set that saw her German opponent run riot. Bouchard then failed to take advantage of a 5-3 lead in the second, and was blown away in the tie-break.

Bouchard burst onto the scene with an impressive 2014 season, which saw her reach the semi-finals of the Australian and French Opens before losing the Wimbledon final to Petra Kvitova.

A run to the quarter-finals in Melbourne is as good as it has gotten for Bouchard in 2015, though, with an arm injury stunting her progress and forcing numerous late withdrawals from WTA Tour events.