Rivals to lovers begins with two people who have reasons to measure themselves against each other. They may compete for a position, disagree about how to solve a problem or believe the other person stands in the way of something important.
The attraction is only one part of the appeal. Readers enjoy watching characters recognise each other's abilities, notice details they once dismissed and discover that the person they considered an obstacle is more complicated than expected.
For the trope to work, the rivalry needs substance. The characters should want something that matters to them. Their competition should reveal personality, values and vulnerabilities rather than exist only to create witty arguments.
The transition also needs to be earned. Respect may arrive before affection. A moment of cooperation can change the dynamic, but it should not erase the history between them. The most satisfying romances let both characters reconsider their assumptions.
Sports settings make the trope especially natural because competition is already built into the environment. In Off the Field, cricket places Advik and Yuhaan in direct competition, while their growing connection challenges the simple labels they have given each other.