text: World road champion Armitstead finished in the peloton to extend her overall lead over South Africa's Ashleigh Moolman-Pasio to eight seconds.
  The 2014 winner Vos won the 119km stage from Nottingham to Stoke in a sprint finish.
  Sunday's 113.2km final stage runs from Northampton to Kettering.
  Vos, who lost the yellow jersey to Armitstead on Friday, won in what was a reduced sprint, with only 20 riders at the front of the race to battle it out after the bulk of the day's climbing was packed into the second half of the stage.
  Boels Domans rider Armitstead had attacked along with Elisa Longo Borghini, Moolman-Pasio and Emma Johansson with a little under 20km remaining, catching and passing lone breakaway rider Emilia Fahlin.
  Armitstead said: "The race stayed together until the climb and then me, Ashleigh and Elisa went on the second Queen of the Mountains [intermediate sprint]. Emilia was in no-man's land so she came back up to us.
  "There was a bit of co-operation for maybe five kilometres and then Emma and Elisa started attacking."
  But the chasing pack, including Vos, battled back and caught them shortly before the 1km-to-go Flamme Rouge to set up the sprint finish.
  She added: "In the final kilometres I could tell [the peloton] were coming back.
  "Coming into the final kilometre there were a couple of turns with up-hill flickers and again Emma and Elisa were attacking, so it was just about covering them.
  "As the group from behind pulled, I tried to put myself in a good position but got caught out a little bit on the last corner."
  Women's Tour 2016 - stage four result
  1. Marianne Vos (NED/Raboliv) 3hrs 7mins 0secs
  2. Leah Kirchmann (CAN/Liv-Plantur) same time
  3. Emma Johansson (SWE/Wiggle High5) same time
  4. Amalie Dideriksen (DEN/Boels Dolmans) same time
  5. Lisa Brennauer (GER/Canyon Sram) same time
  General Classification
  1. Lizzie Armitstead (GBR/Boels Dolmans) 91hrs 2min 56secs
  2. Ashleigh Moolman-Pasio (SA/Cervelo Bigla) +08s
  3. Elisa Longo Borghini (ITA/Wiggle High5) +10s
  4. Marianne Vos (NED/Raboliv) +15s
  4. Amanda Spratt (AUS/Orica AIS) +17s
target: Britain's Lizzie Armitstead stretched her lead in the Women's Tour as the Netherlands' Marianne Vos claimed victory in stage four.