It is hard to say because both faught really hard against their actual opponents for personal reasons.
But since Sakura kept repeating that she really wanted to become a chunin like Sasuke, I think she would have daughter harder.

But Sakura was so weak back then. She had no skills of her own. She fought so hard and tied because it was Ino, but against Hinata I dont think she could have done it. Hinata just had a head start, even if she was always holding herself back.


Now of course she'd beat Hinata without any doubt, but thats a different story.

Hinata was more skilled than Sakura back then.
It may be a different story now...but whatever :P

Hinata would have definitely won. Especially since Sakura had such low tolerance for pain back then. I mean, Sakura and Ino were the only two people who lost their match but didn't have to get emergency treatment for it. Where as Hinata could take anything Sakura would dish out. She got jabbed straight in the heart, twice and kept going! Plus since Sakura didn't know about the Byakugan until Kakashi told her during the fight with Neji, Sakura wouldn't know how vital it is to avoid the gentle-fist before it was too late.