As soon as the race started, Jane flapped her wings and launched herself miles ahead of Rias. The force released by her wings was so powerful that she sent shock waves to the sea, which caused a mini-tsunami.
Luckily, no habited islands were nearby, so no one was hurt.
Rias, who knew something like that would happen, launched herself up into the sky instead of moving forward. Had she moved forward, she would have been pushed by the shock wave created by Jane's flap.
Jane was already miles ahead of Rias the moment the race started, but they still had a long distance to fly.
Rias had limited vampiric power, so she could do tricks like Jane, but she was a master at using her weakness for advantage and adapted to any situation— just like Rudy.
Although Jane was better than Rias in every aspect, Rias' skills, talent, and experience could beat anyone more powerful than her. Rias was Jane's primary source of motivation to do better.