The power of Post-Timeskip Sakura.
Easy. Sakura demonstrated the ability to extract Sasori's poison with a medical Jutsu. My minor modification is reverse it. Instead of taking pathogens out of the body, she puts them into the body. Now, being a medical expert, it is reasonable to assume she knows a crapload about different poisons a ninja may use. She could literally pick any poison in the universe for my plot, but let's make her the one who knocks and go with ricin, or a fantasy equivalent that would exist in the Naruto-verse. Sakura is a doctor, well respected across multiple villages, and has the support of the Hokage. Here's how she'll wipe out an entire teams of Jounin like nothing: give them a checkup. During the checkup she would inform the patients that she detected a minor pathogen and could use her poison removal technique to take it out. However, she's really putting in the ricin. A few days later, our team of hyper-elite Jounin are sick. This is reasonable since they have been working together and it is likely that they would spread any bugs between them. They go to see Sakura, but it is too late. They die while she is administering "emergency treatment." Anybody who is suspicious would quickly be shot down by the Hokage because Tsunade knows the limits of medical ninjutsu all too well. With this application of medical ninjutsu, Sakura is more powerful than entire teams of elite Jounin. Definitely OP. It would take somebody immortal, like Hidan, to survive something like this, but those guys are overpowered in their own rights.
Now, let's up the anti and go with pre-timeskip Sakura.
If the writers had felt like it, they could have made her pretty sick. Her most notable achievement was answering every question on the Chuunin exam without cheating, which were questions that were designed to be so hard that no prospective Chuunin could reasonably answer them. From the musings of the characters, we can tell that these questions consisted at least of geometric calculations and encryption. We also see Sakura's ability to construct traps in the forest of death. So, she has super-studying abilities, excels at geometric calculations, likely involving Newtonian mechanics, and the craftsmanship to carry out those ideas. She was able to construct basic traps while exhausted, starved, dehydrated, beat up, and ill-equipped with no time for forethought. It was essentially improv. Imagine if she was given time to prepare. She also exhibits another remarkable trait that can be used to amplify her already genius-level prowess in this field: shounen-protagonist level willpower. She defeats Ino's soul transfer technique, not by outwitting her, not by manipulating chakra, but by using brute-force willpower to force her out of her body. This is a feat that is unprecedented in Naruto.
So, I have a genius trap-master with insuperable willpower. My minor modification is using this brute force willpower to force her mind to focus on devising traps. The effect would be something like in Phi Brain, where a smart person achieves god-like levels of intellect. However, unlike Daimon Kaito, she would use this power to create elaborate death traps. The tools at my disposal will be all standard canon Naruto equipment, a forest (not outlandish in the Naruto universe; if Shikamaru gets one, then it's fair for me to give one to Sakura.), and preparation.
A team enters Sakura's forest as she stands in the middle entering her hyper-mind state. She has rigged the forest with layer upon layer of traps. Poison, explosions, blades, noxious smoke, you name it. Some are designed to be triggered by the team's movement. They are carefully hidden so as not to be detected, but this is part of the plan. She will use the noise of the traps to determine her enemy's location and also know the best way to counteract it. She will know where her enemies will go before her enemies do and will be able to trigger additional layers of traps on command from her position at the center of the forest. Essentially, her hyper-mind allows her to achieve a level of focus that can manipulate people into impossible scenarios without even getting within 100 feet of them. Pretty OP for a genin if you ask me.