The Sri Lankans, electing to bat, scored 147 all out from 48.3 overs and restricted the Caribbean girls to 138 all out in 50 overs for a winning 4-0 lead in the series.

The remaining games, five and six, will be played today and tomorrow and the West Indies team's technical adviser Gus Logie believes his side could upset the visitors if they are more patient against the spinners and reduce the number of extras they concede.

"Extras are a big problem for us, every time we lose a game we look back at the extras and realise how much it cost us, also we need to be a bit more patient against the spinners; we tend to look too much for the big hits," former Test batsman Logie told CMC Sport yesterday.

Hiruka Fernando (35) and Indika Kankanamalge (31 not out) led the Sri Lanka batting as they suffered four run-outs and were restricted to their lowest total in the series -- though aided by 37 extras, including 33 wides.

Left-arm spinner Shane De Silva was the most successful West Indies bowler with three for 17 off 5.3 overs, while 19-year-old medium pacer Clea Hoyte (1-20), and off-spinners Verena Felicien (1-20) and Julian Nero (1-35) claimed the other wickets.

De Silva, batting at number five, completed a fine all-round performance in top-scoring for the West Indies with 30.

Only openers Nadine George (29) and Glenicia James (18) made significant other contributions, as the home side collapsed from a 60-run first-wicket stand, chasing 148 for victory.

It was the closest game in the series so far and although the West Indies improved their bowling and fielding performance, Logie felt batting inexperience let them down.