The fifth-seeded Jovanovski, whose maiden WTA title came here in 2012, was a 2-6, 7-5, 6-3 winner over Patricia Mayr-Achleitner despite the Austrian converting on seven of eight break points and winning six more points than she lost.
Mayr-Achleitner served for the match up a set and a break at 5-4, and though she got within two points of victory, Jovanovski rallied to win the set. Mayr-Achleitner again got up a break in the third set at 3-2, and again Jovanovski rallied - reeling off four straight games to seal her triumph.
Peer's best WTA outing in the last three years was her runner-up showing here last year. And she looked prepped for another deep run in Baku with a 6-2, 6-4 defeat of No.6 seed Yvonne Meusburger, whom she has yet to drop a set against in three meetings.
Voegele recorded her third consecutive straight set win over Alexandra Cadantu, 6-1, 6-4. Radwanska was up a set on Alison Van Uytvanck when the Belgian had to retire with a stomach illness, handing Radwanska her first WTA main draw win of the year.