A miserable afternoon for the Foxes started in the 21st minute when Steve Howard saw his penalty saved by David James. Brett Pitman then put City ahead before a howler from keeper Chris Weale allowed David Clarkson to secure victory for the hosts in stoppage time.
Eriksson said: "Again we demonstrated what a good team we are by totally controlling the first half. But we missed a penalty and some other chances and Bristol improved considerably in the second half.
"Then we gave away the two goals they scored far too easily with some poor defending.
"It ended up a bad day at the office for us, but we have the chance to bounce back quickly with a big game against Nottingham Forest.
"There are big expectations at the club for this season and I prefer it that way. But we cannot hope to win promotion if we lose games like that."
Source: PA
Source: PA