Natasha and Hawkeye from Age of Ultron.

VS

Daredevil(Ben Affleck) and Elektra(Jennifer Garner).

Round 1: Melee fight.
Natasha with a Spear and Hawkeye with a Combat Knife.
DD has his Club and Elektra has two Sais.

Round 2: Pure H2H.

They fights inside a Karate Dojo.

Who wins and why?