Muguruza, Svitolina and Sabalenka exit as top seeds tumble at Dubai Tennis Championships

It was a day of giant killings at the Dubai Duty Free Tennis Championships on Wednesday as defending champion Garbine Muguruza and world No 2 Aryna Sabalenka were among a host of seeded players to bow out in the second round.

The tone was set when Elina Svitolina, twice a winner of this tournament, was eliminated by Swiss qualifier Jil Teichmann in the first match on Centre Court, the Ukrainian 10th seed going down 7-6, 6-2.

Svitolina was swiftly joined by Polish sixth seed Iga Swiatek, who was narrowly beaten 4-6, 6-1, 7-6 by Latvia's Jelena Ostapenko in a thrilling battle between former French Open champions over on Court One.

"In general it was a good match, but I felt like I could finish it a bit earlier in the third set as I was 3-0 and 30-love up," said world No 21 Ostapenko, who extended her winning record against Swiatek to three matches. "It was a bit of a rollercoaster, but I'm happy with the way I fought until the very last point."

It was then the turn of Dayana Yastremska to deliver her own upset victory when the Ukrainian, ranked No 146 as she makes her way back after being exonerated of a doping violation, knocked out second seeded Czech Barbora Krejcikova 6-3, 7-6.

Soon after Yastremska wrapped up her victory on Court One, Muguruza suffered her own shock defeat over on Centre Court as Russian world No 31 Veronika Kudermetova registered her first win over the Spaniard at the fourth attempt, fighting back from a set down to advance to the quarter-finals 3-6, 6-4, 6-4, despite struggling with a hip injury that required treatment mid-match.

"I know that I can beat top players because I know I can play really good tennis," said Kudermetova, who will face Teichmann in the last eight. "If I have a good day and I