The Grecians took the lead through Steve Tully, who scrambled home a rebound, and Matt Taylor then netted a second as County failed to register a single shot on target.
"We've been encouraging Tully to get forward more, and he's lethal from four yards," said Tisdale.
Tisdale added: "It's our second clean sheet in successive away games. That's very important for us and I'm very proud of the players. It was a lot of hard work and togetherness, and that showed on the pitch."
Source: PA
Source: PA