I don't know based on the rulebook.

The provided rulebook context explains that:

• A Monster can only Yield Tokyo after being wounded (page 6).
• If a Monster loses their last Life Point, they are eliminated and their keep cards and Energy cubes are discarded (page 4).
• When no one is in Tokyo, a Monster can take control of Tokyo (page 5).

However, the rulebook does not specify what happens if the last Monster in Tokyo yields and is eliminated at the same time. It does not clarify whether the attacking Monster (who caused the elimination) immediately takes control of Tokyo, or if Tokyo remains empty until the next opportunity.

To answer this question definitively, the rulebook would need to specify the procedure for taking control of Tokyo when it is vacated due to elimination, especially during the resolution of attacks.

Source: pages 4–6.

Source: Core Rulebook (pp. 3, 4, 5, 6)