Bopara (89) and captain Ryan ten Doeschate (89) added 150 for the fifth wicket as Essex made 341-6.

Hampshire were in trouble early in their reply at 37-3 until Rilee Rossouw (93) and James Vince (47) put on 87 in quick time for the fourth wicket.

But Bopara (3-39) and Peter Siddle (2-18) picked up timely breakthroughs to bowl the visitors out for 230.

Former Hampshire all-rounder Matt Coles (4-48) also made a valuable contribution with the new ball and against the tail enders for Essex.

Essex's second win from five games keeps their chances of reaching the knockout stages alive while Hampshire remain second, level on points with leaders Somerset, who also lost at Gloucestershire.

The hosts posted their highest List A total against Hampshire as Bopara and Ten Doeschate moved them from 147-4 to 297-5 in just over 18 overs.

Rossouw briefly threatened to mount a dramatic run-chase for Hampshire as he struck a half-century from just 39 balls, but when he fell seven short of his century, the game was done.

Essex all-rounder Ravi Bopara:

"When you are on a losing run, you kind of get to a place where you just go 'whatever happens happens' which can bring the best out in a team. We were saying 280 was a good score on there so to get up to 340 was a surprise and we batted them out the game.

"Tendo's innings was unbelievable. It was the innings of the day. It has won us the game. The way he came out and played aggressively and hit the gaps was a serious innings.

"It really set us up nicely. We are still confident of qualifying from the group. We have to hope the performances go our way."

Hampshire first team manager Adi Birrell:

"We weren't very good. We didn't start very well, we let the game get away from us and 341 was a little too much. It is a concern when they get 190 in the last 20 overs and 110 in the last 10. That is what we usually do to the opposition.

"Bopara and Tendo are quality players. They ran really well and they used the dimensions of the ground to their advantage.

"Siddle bowled exceptionally well and put us in trouble early. He put the pressure on us. Saying that, Rilee Rossouw was exceptional. He and Bergy's partnership was outstanding. It put us about 25 ahead of them at the same stage but, unfortunately, we had too many wickets down."