Essex coach Paul Grayson believes his side are still in the hunt for a semi-final place in the CB40.
They chased down 258 to beat Lancashire by six wickets on Sunday to put them level on points with Somerset and Nottinghamshire in their group.
Somerset remain the group favourites as they have two games in hand.
Grayson told BBC Essex: "We're probably going to have to go to Taunton, hopefully to play for first spot, or maybe try to qualify from second."
Grayson praised the contribution of Mark Pettini in Sunday's win, he scored 104, his highest total of the season.
Grayson added: "I'm pleased for Mark because he's had a rough time this summer. He hasn't scored the volume of runs he'd have liked to have done.
"His innings was very good, that should give him confidence for the rest of the season."
All-rounder Ryan ten Doeschate returned for Essex in the match, after being given a two-week rest.