A recessed lighting fixture includes a lamp housing and a separate compact junction box, which contains a power supply that drives the lamp and serves in part to divide the interior cavity of the junction box into two separate wiring compartments. The junction box has two end walls spaced along an axis and a releasably secured, sleeve-like cover (side wall) surrounding and closing the cavity. The cover can be moved axially in either direction relative to the end walls to open the wiring compartments. The junction box and the lamp housing are mechanically connected only by a flexible conduit and a flexible tether, which prevents undue strain on the electrical connections between the joined components. The lighting fixture is particularly suitable for retrofit installations, especially where small-aperture downlights are desired.