World number one Simona Halep breezed past Belgium’s Elise Mertens to reach the third round of the Madrid Open.

The Romanian won 6-0 6-3 in 71 minutes to end Mertens’ 13-match winning streak.

Halep won the first eight games of the match and hit 23 winners as she set up a meeting with Czech Kristyna Pliskova.

Earlier, world number 10 Petra Kvitova won her seventh consecutive match with a 6-3 7-6 (10-8) victory over Puerto Rico’s Monica Puig.

Czech Kvitova, who won the Prague Open on Saturday, had lost both her previous meetings with Puig.

Merten’s winning streak included titles in Rabat, Morocco and Lugano, Switzerland.

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However, Kvitova struck 30 winners and, despite nine double faults, won 68% of points on her second serve.

She will play either Daria Kasatkina or Sorana Cirstea next.

The Fever-Tree Championships at Queen’s is set to have its strongest line-up in its 128-year history with 17 of the world’s top 30 taking part.

World number one Rafael Nadal is one of six players from the top 10 who have signed up to play.

The others are Grigor Dimitrov, Marin Cilic, Juan Martin del Potro, Kevin Anderson and David Goffin.

Britain’s five-time winner Andy Murray, who is currently injured, is also due to play in the event from 18-24 June.

The 30-year-old had hip surgery after pulling out of the Australian Open in January, and has targeted a comeback for the grass-court season.

Feliciano Lopez will defend his title, while Stan Wawrinka, Milos Raonic,, Tomas Berdych and Jo-Wilfried Tsonga are the latest names to be added to the list of competitors.

“To see six of the world’s top 10 players on our entry list before you even get to the names Andy Murray, Stan Wawrinka, Milos Raonic, Feliciano Lopez, Nick Kyrgios and the British number one Kyle Edmund really whets the appetite for a fantastic week of tennis,” said tournament director Stephen Farrow.

“We can’t wait to get started.”

The Queen’s Club Championships, now sponsored by drinks brand Fever-Tree, will be live on BBC television, radio and online.

World number six Karolina Pliskova held her nerve to secure a hard-fought 6-2 1-6 7-5 victory over Victoria Azarenka in round two of the Madrid Open.

Pliskova, 26, eased to the first set only for fellow former world number one Azarenka, 28, to respond by winning five straight games to take the second.

The Belarusian, playing her first clay tournament in two years, hit back from 3-0 down to level the deciding set.

But Pliskova held a tense 11th game before breaking serve to win the match.

The Czech, who won the Stuttgart Open last week, will face Sloane Stephens in round three after the US Open champion beat Australia’s Samantha Stosur 6-1 6-3.

Azarenka missed a large part of last season and this year’s Australian Open due to a custody battle over her son, who was born in December 2016.

The two-time Grand Slam winner will play in the Italian Open next week before making a return to the French Open for the first time since 2016.

• Djokovic beats Nishikori in Madrid Open
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Earlier on Monday, world number two Caroline Wozniacki edged past Australia’s Ashleigh Barty 6-2 4-6 6-4.

The Australian Open champion trailed 4-2 in the deciding set but claimed four straight games to secure victory and set up a third-round tie with Dutch player Kiki Bertens, who beat Latvian 15th seed Anastasija Sevastova 6-1 6-4.

Former world number one Maria Sharapova remains on course for a potential quarter-final against Wozniacki after she beat Romania’s Irina-Camelia Begu 7-5 6-1.

The 31-year-old Russian, who has had an arm injury in recent weeks, will face Kristina Mladenovic in round three after the Frenchwoman beat China’s Shaui Zhang 6-4 4-6 6-3.

Zhang later partnered Johanna Konta to victory in round one of the women’s doubles as they beat Spanish pair Anabel Medina Garrigues and Arantxa Parra Santonja 2-6 6-3 10-3 to set up a tie with fourth seeds Xu Yifan and Gabriela Dabrowski.

British number one Konta will face American qualifier Bernarda Pera in round two of the women’s singles on Tuesday.

Elsewhere in round two, 11th seed Julia Goerges came from a set down to beat Spanish wildcard Lara Arruabarrena 2-6 6-4 6-2.

The German takes on France’s Caroline Garcia in round three after the seventh seed secured a 6-3 7-5 victory over Croatia’s Petra Martic.

Novak Djokovic said his first-round win over Kei Nishikori at the Madrid Open was “exactly” what he needed for his confidence after a run of poor form.

The 30-year-old former world number one has failed to reach the quarter-finals in five tournaments since returning from elbow surgery in January.

But he impressed in beating Nishikori 7-5 6-4 to set up a potential second-round tie with Britain’s Kyle Edmund.

“It was exactly what I needed for my confidence,” said the Serbian.

The 12-time Grand Slam champion, now ranked 12th in the world, said earlier this month that his confidence had been knocked by making a premature return two months after surgery.

British number one Edmund faces Russia’s Daniil Medvedev on Tuesday.

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“I was looking forward to these kind of matches, looking to try to win these kind of matches,” said Djokovic, who split with former head coach Andre Agassi in April.

“I couldn’t ask for a better start. I feel much better about everything that is happening on the court and around tennis in general than maybe two months ago.”

The victory was Djokovic’s first against a top-20 opponent since beating Gael Monfils at Eastbourne in June last year, with the Serbian having to abandon his Wimbledon quarter-final against Tomas Berdych in July because of the elbow injury.

World number 20 Nishikori, who lost to Rafael Nadal in the final of last month’s Monte Carlo Masters, is also making his way back up the rankings after missing six months with a wrist injury.

Elsewhere on Monday, Canada’s world number 24 Milos Raonic beat Argentine qualifier Nicolas Kicker 6-3 6-2 to set up a second-round match against third seed Grigor Dimitrov.

Argentina’s Diego Schwartzman defeated France’s Adrian Mannarino 6-1 6-3 and will next play Spain’s Feliciano Lopez, who beat compatriot Pablo Andujar 7-6 (7-4) 6-3.

Benoit Paire hit 39 winners to upset fellow Frenchman and 15th seed Lucas Pouille 6-2 6-3 to set up a tie with Canada’s Denis Shapovalov.