Hampshire were unable to pick up yet another Royal London One-Day Cup win, despite half-centuries from Liam Dawson (85) and Will Smith (63), as Essex claimed victory in the 50-over fixture at the Ageas Bowl.
After Hampshire lost early wickets, Dawson and Smith helped lead the fightback, but career-best List A figures for Reece Topley (4-26) and debutant Jamie Porter (3-39) ensured Hampshire totalled just 209 in their first-innings effort.
A 122-run partnership between openers Nick Browne (69) and Mark Pettini (57) guided Essex towards the total, and despite late wickets falling, the visitors were able to reach the target with eight overs to spare.
Hampshire stuttered to begin their innings after electing to bat first, with openers Michael Carberry (6) and Jimmy Adams (23) departing inside the opening powerplay overs.
Skipper James Vince (2) and Adam Wheater (2) then also fell in quick succession and the hosts looked to be struggling at 36-4 with Topley and Porter doing much of the early damage.
The departure of Joe Gatting (17) soon after furthered the home-sides troubles at 68-5, but Dawson and Smith sought to lead the recovery with the duo ensuring Hampshire passed 100 without further loss.
Both batsman looked to be in good-touch as they battled through some efficient spells of bowling and looked to be building nicely. Dawson was first to reach his well-made half-century before Smith then reached the milestone shortly after to mark the hundred partnership - a stand that saw the score soon move to 192-5.
However when both batsmen departed at the hands of Essex seamers Porter and Topley, another small collapse ensued, and as the final five wickets fell for just 17 additional runs, the innings concluded on 209 with just over four overs still remaining.
The visitors began well in reply, with openers Browne and Pettini ensuring Essex reached 80-0 from the opening 15 overs.
Browne was first to his half-century, the left-hander batting with excellent fluency, whilst Pettini, who batted with slightly more caution, neared his fifty as the score swiftly moved onto 122-0.
Dawson (1-40) made the breakthrough with Browne clean-bowled, but Pettini continued to advance beyond his half-century as he guided his side towards the required target.
Late wickets for Chris Wood (1-14), Will Smith (1-24) and Mason Crane (1-53) helped stall the away-side, but with eight overs still remaining, they reached the total to deny Hampshire a third 50-over win this season.