Gillingham boss Peter Taylor blasted his side's poor first-half show following their 2-1 defeat at Bristol City.
With the visitors looking the more likely winners, City midfielder Simon Gillett, on loan from Nottingham Forest, unleashed a spectacular shot with his right foot that ripped into the top corner of the net.
Sam Baldock had broken the deadlock for the hosts after 27 minutes, chesting down a precise chip forward from Wade Elliott and hammering a sweetly-struck right-footed volley past Stuart Nelson from 15 yards for his 18th goal of the season.
Gillingham improved after the break and deservedly equalised in the 65th minute when Ade Akinfenwa headed back across goal from a right-wing corner and substitute Charlie Lee blasted home from close range.
That was not enough to satisfy Taylor, who said: "We cannot afford to start games like we did here.
"Bristol were much sharper than us. We improved in the second half and have lost to a tremendous goal, but I want that sort of performance for 90 minutes.
"The first half wasn't good enough. There are a lot of teams in this division who only start to play when they have some reason to fight back.
"We haven't been like that recently and we don't want it to become a habit.
"To be fair to the players, they kept going, we got a good goal and perhaps could have gone on to win at that point."
City made a bright start, which saw Bobby Reid just fail to connect with a Baldock cut-back and Jay Emmanuel-Thomas fail by inches to slide in and convert Reid's cross.
Gillingham found it hard to create first-half chances. Their best effort was a fierce 51st-minute shot by Cody McDonald, which was well smothered by Frank Fielding.