Francois Zoko snatched an injury-time winner for Carlisle over Yeovil.
Lee Miller gave the Cumbrians the lead from the spot after Bondz N'Gala handled Jon Paul McGovern's cross, but Jon Obika equalised at the near post.
Paddy Madden restored the hosts' lead after going clean through on goal, before Dominic Blizzard combined with Jonathan Grounds to restore parity.
Zoko ensured a dramatic victory late on when he poked home from close range following a goalmouth scramble.
VIEWS FROM THE DRESSING ROOM
Carlisle assistant manager Graham Kavanagh told BBC Radio Cumbria:
"Start of every season you're looking and thinking, 'where are we with squad? Have we improved, are we better than we were last season?'
"We genuinely felt we were and we were saying, 'if we can get ourselves into the top half of the table come Christmas we can revaluate and reassess it and hopefully there is more money to improve the squad'.
"We're now in the top six and obviously that's where we want to remain for the remainder of the season, it'll be an incredible achievement."
Yeovil Town manager Gary Johnson told BBC Somerset:
"Defensive mistakes cost us. It was defensive indecision for all three goals, it was certainly poor defending.
"We're going to have to have a good look at that because when you score two goals and have that amount of chances two goals should be enough to win it, anywhere. We should be good enough not to let in three goals.
"The lads deserved to be back at 2-2 for the second half performance, we were still going for it without leaving ourselves opened, but we really should have got something out of the game.
"We had lots of opportunities, it was a very open game. The indecisiveness is costing the club results."