The first round of the Bad Homburg Open saw two of the Top 4 seeds taking on German lucky losers; and while No.4 Beatriz Haddad Maia survived a stern test from Tamara Korpatsch to advance 6-1, 7-6(6), Jule Niemeier sprung an upset, edging No.1 Maria Sakkari 2-6, 6-2, 7-6(4).

Bad Homburg: Scores | Draws | Order of play

Haddad Maia will next face Anna Blinkova, who came through 6-4, 6-2 over wild card Bianca Andreescu. Former US Open champion Andreescu, who is playing the third tournament of her comeback from a back injury, reached her second grass-court final two weeks ago in 's-Hertogenbosch. However, the Canadian was unable to reproduce that form as she fell in an error-strewn 75 minutes.

Niemeier's win is the former Wimbledon quarterfinalist's fourth career Top 10 victory, three of which have come on grass. Previously, the 24-year-old had defeated Anett Kontaveit at Wimbledon 2022 and Ons Jabeur at Berlin 2023.

Sakkari had originally been slated to face Elisabetta Cocciaretto, but the Birmingham finalist withdrew due to illness. Niemeier, who had fallen in qualifying to Diane Parry, only found out she would be competing half an hour before the match began. This was evident in her slow start: she committed 19 unforced errors in the first set, and only began to find her rhythm towards its close.

Bad Homburg unlocked promo

WTA

However, Niemeier began to find her range with a series of pummelling forehands and delicate volleys, dominating the next two sets to advance to a 5-3 third-set lead. Her play became edgy as she attempted to close out the win, and Niemeier netted a backhand on her first match point at 6-5. But she held her nerve in the tiebreak, which concluded with two consecutive Sakkari double faults.

Sakkari is now on a four-match losing streak dating back to Rome. Niemeier advances to face wild card Paula Badosa in the second round.

Haddad Maia quells Korpatsch on eighth match point in Bad Homburg opener

Haddad Maia had not dropped a set to Korpatsch in three previous meetings, and just about preserved that perfect record against the World No.75. The Brazilian had lost her first grass-court match of the season to Ekaterina Alexandrova last week in Berlin, but her touch at net was on superb display here.

Korpatsch began to get a foothold in the match thinks to a series of precise down-the-line winners, and saved three match points -- one down 5-4 and two more down 6-5 -- to force a second-set tiebreak. Haddad Maia advanced to a 6-2 lead, but a medical emergency in the crowd necessitated a 20-minute stoppage -- and on resumption, Korpatsch promptly saved another four to level at 6-6.

But Haddad Maia was able to recover, finding a pair of strong winners to close out the win on her eighth match point.