Roared on by a capacity crowd Halep did not disappoint, withstanding some early pressure to run out an ultimately comfortable 6-4, 6-2 winner in an hour and 12 minutes.
After an even start, Halep hit the front in the seventh game, pouncing on an inviting second serve to capture the set's solitary break. Unmoved by the partisan crowd, Kovinic competed on even terms in the second set, too, but as the contest wore on the top seed's ability to make her play one extra shot began to take its toll.
Serving at break point down in the third game, Kovinic fluffed a routine volley when Halep slid to track down another seemingly lost cause. This signaled the beginning of the end, and despite a spirited late rally she was unable to prevent Halep setting up a semifinal meeting with Vania King.
In the day's first match, No.4 seed Laura Siegemund laid down a marker with a brisk 6-2, 6-1 win over Polona Hercog. King was equally impressive in beating Pauline Parmentier, 6-3, 6-1, to reach her first WTA semifinal since 2014.