England team-mates Jenny Duncalf and Tania Bailey battled through to the quarter-finals of the Women's World Open Squash Championship in Madrid after victories over compatriots in the second round of the sport's biggest-ever women's event in the Spanish capital.

Duncalf, the ninth seed from Yorkshire, upset Vicky Botwright in 48 minutes after the No6 seed from Manchester retired with a back injury with the score standing at 9-4, 9-6, 5-3.

"I felt a twinge on my right side when Jenny pushed me forward at the end of the second game," explained Botwright, the England No3.

"It was shortly after the British Open (in September) that I played a league match when I felt a similar twinge, and woke up the next morning with the left side of my body paralysed.  Tania Bailey was my saviour - luckily she was staying with me that night and helped me get dressed and took me to the EIS in Manchester.  It was two days before I regained feeling - and some time before I was back to normal.

"I guess I just haven't been put under that kind of pressure since the British Open - but I didn't want to risk anything like that again, so I had to retire.  If I have to lose to anybody like that, I'd rather it was to an English player!"

Duncalf seemed surprisingly downbeat following the win which takes her into her maiden World quarter-final:  "It's never nice to win like that - but I thought I played well and deserved to win," said the 24-year-old.

"I had a game plan and stuck to it - I didn't make many errors and was hitting a good length.  I'm looking forward to playing on the glass court - though I hear the weather forecast suggests that it will be only one degree!  But I'm ecstatic really - it's good to be in my first world quarter-final!"

One of the bravest wins of the day was achieved by fourth seed Tania Bailey in the other all-English last sixteen clash.  Struggling for the second day with a recurrence of sinusitis, the England number one from Lincolnshire fought back from a game down to beat 11th seed Laura Lengthorn-Massaro, from Preston, 8-10, 9-5, 10-9, 9-3 in 75 minutes.

"I can't believe I managed to get through that," said the 28-year-old from Stamford who was clearly again having serious difficulty with her breathing.  "I felt I needed to win the first game - and when I didn't, I didn't think I could win the match. 

"But I felt I then played thoughtful squash.  I was feeling light-headed and kept having to take deep breaths.  I never went into the match thinking I was going to win - Laura is such a tough player," added Bailey, who goes on to meet former world champion Vanessa Atkinson.

"I look forward to playing on the glass court - where conditions surely couldn't be more different from those here.  I've actually beaten Vanessa the last four times I've played her - but that followed about eight wins in a row by her.  But she's playing a lot better at the moment."

Alison Waters, the 12th seed from London, put up a brave fight against Rachael Grinham - taking the first game against the third seed from Australia before going down 4-9, 9-6, 9-4, 9-5 in 71 minutes.

2nd round results:
[10] Shelley Kitchen (NZL) bt [1] Nicol David (MAS) 9-0, 9-1, 2-9, 3-9, 9-6 (69m)
[5] Natalie Grainger (USA) bt [13] Engy Kheirallah (EGY) 9-2, 9-0, 9-0 (26m)
[3] Rachael Grinham (AUS) bt [12] Alison Waters (ENG) 4-9, 9-6, 9-4, 9-5 (71m)
[9] Jenny Duncalf (ENG) bt [6] Vicky Botwright (ENG) 9-4, 9-6, 5-3 ret. (48m)
[8] Vanessa Atkinson (NED) bt [15] Kasey Brown (AUS) 9-5, 9-0, 9-0 (35m)
[4] Tania Bailey (ENG) bt [11] Laura Lengthorn-Massaro (ENG) 8-10, 9-5, 10-9, 9-3 (75m)
[7] Omneya Abdel Kawy (EGY) bt [16] Annelize Naude (NED) 4-9, 10-8, 9-5, 9-4 (59m)
[2] Natalie Grinham (AUS) bt [14] Rebecca Chiu (HKG) 9-5, 9-5, 9-4 (40m)

Quarter-final line-up:
[10] Shelley Kitchen (NZL) v [5] Natalie Grainger (USA)
[3] Rachael Grinham (AUS) v [9] Jenny Duncalf (ENG)
[4] Tania Bailey (ENG) v [8] Vanessa Atkinson (NED)
[2] Natalie Grinham (AUS) v [7] Omneya Abdel Kawy (EGY)