Rodriguez, 45, posted a photo of himself and Lopez sitting side-by-side on a private jet as the songstress held up the lyric sheets for her performance.
"I can’t stop thinking about Wednesday and Jen’s performance at #Inauguration2021," Rodriguez wrote in the caption. "It was such an iconic moment -- one I’ll never forget."
"I can’t express how proud I am of her and how privileged I felt just to be in attendance," he continued. "It truly was awe-inspiring and so patriotic."
During the inauguration of President Joe Biden and Vice President Kamala Harris on Wednesday, the 51-year-old singer took the podium to sing one of the United States' most famous folk songs, Woody Guthrie's "This Land Is Your Land," throwing in a "Let's Get Loud" moment.
"One nation under God, indivisible, with liberty and justice for all," Lopez also said in Spanish before closing out with "America the Beautiful."
"On the flight home, she showed me her lyrics sheet, and the significance of her performance really began to sink in," Rodriguez wrote. "Can you believe she was the first person to sing in Spanish at an inaugural event?"
Rodriguez commended Lopez for yet "another historic and groundbreaking achievement for one of the most talented and driven people the world has ever seen."