Neina Graham, 35, of Church Street, Whittle le Woods, Chorley, Lancashire, twisted her knee in the accident in August 1999 and was in such extreme pain that medics had to give her morphine.
The council denies all liability in the case - disputing that there was any defect in the flagstone which 'gave rise to a forseeable risk of injury' or that any defect 'caused' her fall - and, in March last year at Preston County Court, Judge Appleton threw out Ms Graham's claim.
But appeal court judges have now overturned Judge Appleton's decision and ordered a complete re-hearing of Ms Graham's damages claim before a different judge.
Lord Justice Brooke, sitting with Lord Justice Rix and Lord Justice Maurice Kay, said the case was 'noteworthy' because it was the first time that the appeal court had conducted an entire, two-hour long, hearing by video-link, with barristers addressing the court from Preston.
He said there had been a 'procedural irregularity' in the hearing before Judge Appleton which 'did cause injustice' and required a re-hearing of Ms Graham's claim.
One expert, the judge said, had commented on the 'extreme' nature of Ms Graham's injuries and had expressed puzzlement 'that a mere trip in the garden could have done so much damage'.
In her evidence before Judge Appleton, Ms Graham agreed she was 'partly to blame' for the accident in not looking down on the path as she went along.
But Lord Justice Brooke said she had given a 'graphic description' of the accident and its aftermath, saying she had 'never been in such pain'.
An ambulanceman had to give her morphine on the spot so that, by the time she arrived at hospital, 'she did not know what was going on around her'.
No date was set for the re-hearing of Ms Graham's damages claim before a different judge at Preston County Court.
STRAND NEWS SERVICE