ESSEX all-rounder Ravi Bopara admitted the Eagles fell short of a defendable total as they lost their second T20 Blast match in a row.
Explosive half-centuries from Michael Carberry and Matt Coles pointed the way to a comfortable five-wicket victory for Hampshire as they easily chased down Essex’s total of 167 for nine at Chelmsford.
Essex still remain top of the table but need a point from their final game of the group stages against Sussex on Friday to ensure they get a home quarter-final draw.
Bopara said: “We needed a total of 200 on that pitch and once we fell well short, it was always going to be difficult to contain them.
"We need our top-five batsmen there for 17 overs but that never happened tonight, of course it's disappointing to lose although we know we have a home tie in the quarter-finals.
"We need the momentum of victories and that makes it important we win our final match before going into the quarter-finals a week later."
Set a victory target of 168, the visitors lost James Vince, lbw to Graham Napier, to their first ball of their reply but fellow opener Carberry smashed 57 from 28 deliveries to leave his side well positioned.
But even his brilliant effort was eclipsed by Coles, who posted his half-century from 18 balls - the quickest 50 of the season - and although he was caught at cover for 54, Hampshire surpassed Essex's 167 for nine with 15 balls to spare.
Carberry's effort contained seven fours and four sixes, the last of which was huge drive against David Masters that carried him to his half-century from 25 balls before Bopara ended his innings by bowling the left-hander in his first over.
Although Napier returned to trap Glenn Maxwell lbw with a perfect yorker for 25 before the total had moved into three figures, his dismissal only served to herald the arrival of Coles, who unleashed strokes of awesome power that brought him five sixes among eight boundaries.
Essex also got off to a poor start after losing the toss when Jesse Ryder was bowled for a duck by Will Smith, who went on to undermine the home side's innings as he varied his flight and pace intelligently.
The off-spinner proved so difficult to put away that he picked up his three wickets at a cost of only 17 runs and among his victims was Ryan ten Doeschate, who struck three sixes in his 36 made from 20 balls before he holed out to the long-on boundary.
Opener Mark Pettini also struck three sixes when making 44 from 35 balls before he was stumped by Adam Wheater as left-arm spinner Liam Dawson tempted him down the pitch.
Tom Westley was the only other notable contributor with the bat for Essex with 31 from 13 balls but the home side failed to provide any momentum, their last five overs producing just 36 runs and the loss of four wickets.
Hampshire, who moved into second place in the South Division, are now left relying on Surrey to lose their final two matches to be sure of a home tie in the last eight.