The sizzling moment was captured in an Instagram video A-Rod posted, which also featured party guests at the Coral Gables, Fla., celebration singing "Sweet Caroline."
On Friday night, Lopez, 50, paused her concert in Miami to sing happy birthday to Rodriguez.
TMZ reports that the four-tiered cake she had wheeled out for A-Rod had his name emblazoned on it with Swarovski crystals and featured an edible baseball jersey and bat. The dessert was estimated to cost around $3,000.
She gushed on Instagram, "Celebrating you today and everyday my love... you are one of a kind, my hurricane and my calm in the middle of the storm...thank you for being such a beautiful light in my life... wishing you the most beautiful birthday ever!!! HAPPY BIRTHDAY 13!!!"
Rodriguez also gifted his future bride with a brand new Porsche to celebrate her milestone.
In a sweet Instagram video for her big day, Rodriguez gushed, "Hi baby girl. Just wanna wish you a Happy Birthday. I cannot believe this baby girl. Since we've been together, you have made me feel like everyday is my birthday. Thank you for your passion and your energy and your inspiration, and your endless pursuit to be the best at everything that you do."
He continued, "You're simply the best partner in life. The best daughter. The best mother. The best performer. We love you. Your fans love you. Your children love you. And I love you. Let's make this birthday a very special one. Te quiero mucho."