Preheat the oven to 350°F (175°C).
Grease and flour a 9×13 inch baking pan or line it with parchment paper.
In a large mixing bowl, combine the lemon cake mix, water, vegetable oil, and eggs.
Add the fresh lemon juice and lemon zest to the mixture.
Using an electric mixer, beat the mixture on medium speed for 2 minutes until smooth.
Pour the batter evenly into the prepared baking pan.
Bake in the preheated oven for 28 to 32 minutes, or until a toothpick inserted into the center comes out clean.
Remove the cake from the oven and allow it to cool in the pan for 10 minutes.
Transfer the cake to a wire rack to cool completely before serving.