Bacsinszky was facing her first big test of the tournament against 22-year-old Kateryna Kozlova, an opponent who took her to three sets in their last encounter at Nottingham.

“This was a tough one for sure,” Bacsinszky said in her post match interview. “Kozlova is playing better and better every week, so this was a tough match.”

The rapidly rising Kozlova might be ranked No.117 but she sits at No.75 on the Road To Singapore Leaderboard due to her impressive results this year. In St. Petersburg she turned heads with her run through qualifying to the quarterfinals – beating Laura Siegemund and Elena Vesnina along the way – and last week she notched a semifinals appearance in Istanbul.

Bacsinszky drew first blood early on, breaking Kozlova’s in the first game of the match and again to go up to a 4-1 lead. The Swiss’ heavy high-bouncing forehands kept Kozlova back on her heels and out of position. Kozlova broke Bacsinszky’s serve to start mounting a comeback in the final games of the set, but the top seed quickly broke right back close out the set.

Kozlova found her pace in the second set, and put together the play that has impressed throughout the year. She overpowered Bacsinszky from the baseline and took the set to level the match. But the Swiss player put the mid-match dip behind her and won the deciding set after two hours and twenty minutes.

“She raised her level in the second set,” Bacsinszky said. “She was pushing more against me and had me more on defense. It was hard to hit winners against her.

“But I found my way to change things in the third set and in the end I was lucky enough to win the last point.”

Bacsinszky’s opponent in the quarterfinal is Johanna Larsson, who knocked out Teliana Pereira 6-4, 6-4.

Elsewhere, New Zealand qualifier Marina Erakovic had a bittersweet entry to the quarterfinals – she was up 6-4 against the No.7 seed Lesia Tsurenko when the Ukrainian was forced to retire due to pain in her right thigh from an injury sustained during fitness training.

“It’s always tough when you win like that,” Erakovic said afterwards. “You never want to see your opponent injured – I feel sorry for Lesia and hope she’s okay.

“But, you know, good for me. I’ve got through five matches here, which is great. I’m gradually playing better and better each match which is what you want.”

She sets up a quarterfinal clash against Aleksandra Krunic next round, who earlier ousted the No.2 seed Ekaterina Makarova, 6-2, 6-2 in the day’s biggest upset.

“I’ve never played her before but I know her,” Erakovic said. “It’s another challenge, another match, another chance to compete and keep improving my game. That’s what I’m thinking about.”

“Here in Rabat every day is a nice day – the sun is always shining, so tomorrow should be a good day.”