A321
Situational Awareness; Fatigue
Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Flight Crew Took Evasive Action; Flight Crew Became Reoriented
Airport; Human Factors
On the TYSSN3 RNAV arrival for the LAS ILS 25L approach. We were in [night] VMC with unlimited visibility. South of the localizer and the PRINO intersection; Approach Control asked us if we had the runway in sight. After confirming we had the runway in sight; Approach cleared us for the visual. We initially went direct to SHAND and then direct RELIN. We had initially set 4;900 feet into the altitude alert and started a descent; I was expecting to level off at this altitude but realized that this was not going to occur. I verbally stated that we should level off at 4;900 feet but with the open descent mode selected we continued to descend. It was then that the autopilot was disengaged and a climb was initiated. At some point about that time we received a GPWS warning. We continued to climb and the warning stopped. Factors:1. Is was approximately XA:00 for us and the second leg with an origination in [the east]. This was the backside of the clock for us and fatigue was a big factor.2. With unlimited visibility we elected to take the visual when prompted by approach control; if not we would have just continued with the ILS. 3. The altitude alert was changed to 3;800 feet most likely when direct RELIN was entered. Probably due to fatigue; I missed the altitude change confirmation and the waypoint change confirmation.
A321 First Officer; as the Pilot Monitoring; reports a terrain warning during a night visual approach to Runway 25L at LAS after arriving via the TYSSN3 and going direct RELIN.