I agree with Keisha, this is where the buyer's agent should be using their phenomenal negotiating skills to determine some solutions. And that should have started 2 weeks before your schedule close of escrow date.
First Identify all of the parties: there's the seller, the tenants, your lender (I'm assuming), you as the buyer and your two agents. Anyone else?
Next, you're saying that the delay is one more week. Are you sure? What will happen if they're not out in another week? Why is the tenant delayed? What is it costing you? (will your loan rate expire? cost to extend your current housing? pay for a hotel or extra storage during the interim? other costs?) What is the impact on the seller for the delay?
What are you options? sit and wait? Cancel the contract? any way to compel them to complete the contract? Once you have all the factors identified, then you can consider options. To sit and wait is not a good solution. Experience has shown me that the delay could be longer, the home may not be transferred clean and in good condition...in other words you're at the mercy of everyone else and that provides a sour taste as you move into your new home.
In terms of legal actions, the contract states everything. You can always have a lawyer try to enforce the contract but that's most likely going to create more complexity...you just want the home. Still you may want to consult with an attorney to get their view as well.
My best suggestion is to not wait and do nothing. The seller and tenant are not performing according to the contract. What's to say when and under what condition they will provide you the property?