JESSE Ryder's explosive innings helped Essex to a four-wicket victory against Middlesex in their NatWest Twenty20 Blast South Group match at Chelmsford to keep them on course for a quarter-final place.

The New Zealander reached 59 from just 27 deliveries, with two sixes and eight fours in his innings as Essex surpassed their opponents' 150 for five total with eight balls to spare.

But Ryder needed two huge slices of luck on the way as George Scott spilled a pair of easy catches.

First of all he put down a skier at deep square leg when the batsman had scored 36 and then failed to accept an off drive at long-off when the left-hander had added a further four runs.

But Ryder did not escape a third time when he put up a simple catch to Ollie Rayner at point to give Mitchell McClenaghan some consolation for the mauling he suffered at the start of the innings when he conceded 21 runs in his opening over.

It was an over in which Mark Pettini and Ryder struck him for huge sixes as they went on to raise the fifty stand in the fifth over before the former holed out against Harry Podmore.

Ryder drove and pulled with customary venom and once he was out it was Westley, despite losing partners Ravi Bopara and Ryan ten Doeschate cheaply, who took Essex to one run away from victory.

With the scores level, Westley drilled a ball from Dawid Malan to Neil Dexter at mid-off.

Westley had made 45 from 39 deliveries with the assistance of six boundaries.

Without any addition to the score, Liam Dawson was bowled by Gurjit Sandhu, but Graham Napier soon collected the required single that keeps his side's quarter-final aspirations alive.

Middlesex had earlier been unable to break free of an accurate attack backed up by some fine ground fielding.

Eoin Morgan could only manage three boundaries in an innings of 21 spanning 25 deliveries while John Simpson needed one more ball to gather the same number of runs before he was bowled by Graham Napier.

It was left to 21-year-old Nick Gubbins to provide the one note of sustained aggression after he had lost opening partner Malan in the first over sent down by Reece Topley.

Gubbins hit Topley, David Masters and Napier for sixes and also struck three fours while making 46 from 34 balls. He was eventually caught at long-off by Napier off attacking off-spinner Westley whose two overs cost 10 runs.

But it was Australian paceman Shaun Tait who really tightened the screw, picking up the wickets of Morgan and Ryan Higgins in a four-over spell costing just 19 runs.

Essex captain ten Doeschate said of his team's prospects: "We'll probably have to beat Kent in our last match to qualify but we have the momentum having won six of our last eight games.

"But we need to do better in the middle order and not rely on our top three batsmen as we have tended to do.

"Our bowling was superb and I was delighted the way that Reece Topley and Graham Napier came back late on."