"But during the race, it caught up with me and I started having dizzy spells and so I had quite a struggle all the way from Okataina to the Falls, and almost pulled out. But my support crew made me go down to the 70km mark and then I made the call to go to the 87km distance."
She said by that stage, a further two hours of running would have been too much for her.
"I dug deep and gave it everything to make it to the finish line. I didn't realise that I ended up with a fairly good time we had a bit of a giggle because I didn't realise [I'd won] until late [Saturday] night when we had a look at the results."
She said shortening her run was the right thing to do.
"I'd done the 100 the year before, so it wasn't like I needed to do the 100 to have a tick in a box, so I wasn't disappointed. It was a real tough day for me mentally, because I was very close to pulling out."
As well as last year's ultramarathon, Webb has completed five full-distance ironman triathlons.
She was heavily involved in helping race director Paul Charteris organise the ultramarathon and was also one of the driving forces behind the dog-friendly Dogaine team fun run last Thursday.
She ran to raise money for Kawerau SPCA.
"We adopted our dog from Kawerau SPCA and I got involved with them and realised how, with being quite remote, it's really quite hard for them to get cash funds."
Webb had no definite plans for her next race, and said the priority now was recovery.
"I need to look after myself quite well now, and then I'll see, depending on what life throws at me. But I'm always out running with the dogs."
Webb's 87km race winning time was 10:47:39.