WWE/WWF history: Identify The Rock's opponent in the main-event WWF Championship match at WrestleMania XV (1999). Context: Event date 28 March 1999; venue Philadelphia, USA; main event featured The Rock defending the title. Choose the opponent's ring name.

Given data

• Event: WrestleMania XV (1999).
• Subject: The Rock's opponent in the main event for the WWF Championship.

Approach
Recall the 1999 marquee feud and the title match booking.

Identification
The main event was The Rock vs. Stone Cold Steve Austin, with Austin winning the WWF Championship.

Eliminations
Mankind, Triple H, The Undertaker, and Big Show were involved in other bouts/angles around that card but were not The Rock's main-event opponent.

Final Answer
Stone Cold Steve Austin