England remain unbeaten in the Women's World Cup after Nat Sciver-Brunt's sensational century and a remarkable spell of 4-17 from Sophie Ecclestone set up a crushing 89-run win over Sri Lanka in Colombo.

Having put England in to bat, Sri Lanka were left to rue dropping Sciver-Brunt on three, as she punished them with a run-a-ball 117 in England's competitive 253-9.

The game was delicately poised with England 179-6 after 40 overs, but the captain timed her acceleration to perfection with 49 runs coming from the last five.

In reply, Sri Lanka's captain and key batter Chamari Athapaththu retired hurt early in their innings, but fellow opener Hasini Perera and Harshitha Samarawickrama led a promising recovery to 98-2.

But the co-hosts' lack of batting depth cost them, despite Athapaththu's return to the crease before she fell for 15, and they finished 164 all out in the 46th over, Ecclestone's often-unplayable spell of turn and bounce doing the damage.

England's third win in a row puts them top of the eight-team table, one point above defending champions Australia.

Earlier, Sciver-Brunt played a lone hand as the rest of England's top order made promising starts but were unable to capitalise, with opener Tammy Beaumont's 32 the next-highest contribution.

Amy Jones was run out for 11 and Beaumont was caught in the covers, before Sciver-Brunt and former captain Heather Knight consolidated with a patient stand of 60.

Knight was caught sweeping for 29 and England suffered another middle-order wobble to spin, including the loss of Emma Lamb and Alice Capsey to Inoka Ranaweera in the 35th over.

The discipline of Dean stabilised England again as she added 38 for the seventh wicket with Sciver-Brunt, which allowed the skipper to kick on at the death and ensure they had set a winning score.

England will look to maintain their winning run against Pakistan, also in Colombo, on Wednesday.