First, Morrisons said its diesel would be reduced by up to 2p a litre from Wednesday morning.
Supermarkets have announced that they are driving down the cost of diesel, giving some cheer to hard-pressed motorists.
Then Sainsbury's announced a similar diesel reduction - also taking effect from Wednesday.
And thirdly, Asda said it was cutting its diesel by up to 2p a litre from Wednesday as well.
Morrisons petrol director Mark Todd said: "A drop in wholesale prices combined with an improved exchange rate has provided us with an opportunity to pass a saving on to customers and continue to offer some of the lowest prices on the market."
Morrisons has 314 petrol stations across the UK.
Sainsbury's fuel buyer Chris Biggs said: "We're always looking at ways to help our customers save money which is why we're pleased to announce that from tomorrow we will be reducing diesel prices by up to 2p per litre across our 280 forecourts."
Andy Peake, Asda's petrol trading director, said: "From tomorrow, everybody filling up at an Asda fuel station will pay no more than 137.7p a litre for diesel."
The most expensive petrol in the world