Round-up: Caroline Wozniacki survives meltdown to beat Denisa Allertová, Petra Kvitova through

The fifth seed beat the Czech world number 83 6-1 7-6(6) in a match that would have been wrapped up inside an hour had Wozniacki not completely lost her timing in the second set.

The start of play on court 12 was delayed by morning rain in London, but Wozniacki came out looking like she still wanted the match wrapped up the match in time for lunch.

Wozniacki raced into a 5-0 lead in just a quarter of an hour, going on to claim the opening set in just 23 minutes.

She then quickly went a double break up in the second set as she led 5-1 - but just as her passage seemed assured, Allertova reeled off five games in a row to lead 6-5.

Wozniacki, reeling, dug in to hold serve and force a tie-break, but Allertova pushed hard and there was scarcely more than a point between them throughout.

The former world number one held her nerve at the vital moments, however, missing one match point at 6-5 but wrapping things up just a couple of points later to make the third round at the All England Club for the first time since 2012.

Defending champion Petra Kvitova beat Japan's Kurumi Nara 6-2 6-0 as she continued her ominous form.

Kvitova, who hit 23 winners alongside 10 aces as she beat Nara in 58 minutes, said: "It was a good match from my side. I was really expecting a tough match because I saw a little bit - of her ability - when she played Venus Williams here last year."

"I was really prepared and I'm really happy with how I played today, how I managed to win."

Kvitova has dropped only three games in two matches.

2-Petra Kvitova (Czech Republic) beat Kurumi Nara (Japan) 6-2 6-0

5-Caroline Wozniacki (Denmark) beat Denisa Allertova (Czech Republic) 6-1 7-6(6)

Magdalena Rybarikova (Slovakia) beat 8-Ekaterina Makarova (Russia) 6-2 7-5

10-Angelique Kerber (Germany) beat Anastasia Pavlyuchenkova (Russia) 7-5 6-2

13-Agnieszka Radwanska (Poland) beat Ajla Tomljanovic (Croatia) 6-0 6-2

15-Timea Bacsinszky (Switzerland) beat Silvia Soler Espinosa (Spain) 6-2 6-1

Casey Dellacqua (Australia) beat 17-Elina Svitolina (Ukraine) 7-6(3) 6-3

18-Sabine Lisicki (Germany) beat Christina McHale (U.S.) 2-6 7-5 6-1

20-Garbine Muguruza Blanco (Spain) beat Mirjana Lucic-Baroni (Croatia) 6-3 4-6 6-2

21-Madison Keys (U.S.) beat Elizaveta Kulichkova (Russia) 6-4 7-6(3)

Olga Govortsova (Belarus) beat 25-Alize Cornet (France) 7-6(6) 2-6 6-1

Kristyna Pliskova (Czech Republic) beat 26-Svetlana Kuznetsova (Russia) 3-6 6-3 6-4

28-Jelena Jankovic (Serbia) beat Evgeniya Rodina (Russia) 6-7(4) 6-1 6-3

31-Camila Giorgi (Italy) beat Lara Arruabarrena Vecino (Spain) 6-0 7-6(5)

Monica Niculescu (Romania) beat Jana Cepelova (Slovakia) 6-3 6-3

Tatjana Maria (Germany) beat Duan Yingying (China) 1-6 6-2 10-8