Phil Jevons inspired Yeovil's comeback, hitting a brace from the penalty spot as they scored five after half-time.
Boss Gary Johnson said: "To get five goals away from home - all in the second-half - is pretty extraordinary.
"Although we are right up there near the top, I still have a lot of sadness that Cambridge are bottom of the League after what we achieved when I was there in the 90's."
Swansea stay in third place after steamrollering Boston at the Vetch Field.
Although the Iron's lead at the top of the table was cut, their advantage over fourth spot increased to 11 points thanks to Southend's surprise loss at home to Mansfield.
Macclefield and Northampton bolstered their play-off challenges with wins over Wycombe and Bury respectively.
Shrewsbury boosted their hopes of surviving relegation with a 4-0 demolition of Darlington, who face Scunthorpe on New Year's Day.