Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Wake Vortex Encounter
Flight Crew Regained Aircraft Control; Flight Crew Returned To Clearance
Procedure; Environment - Non Weather Related
Rwy 25L HKG we encountered wake turbulence passing 800 feet on departure behind a B777.  Approximate 30 degree bank left and loss of roughly 5 degrees of required climb pitch attitude with decreasing airspeed.  We disconnected the autopilot; recovered from the upset; re-automated; re-established ourselves on the departure SID; and notified ATC of the wake turbulence upset.  No issues with ATC were noted for being off track and we were still able to make the min 205 speed at Prawn intersection.
B747-400 Captain reported encountering wake turbulence departing VHHH in trail of a B777.