And the British rocker went to extraordinary lengths to let the fan know it - a smart move, considering the fan was none other than his Oscar-winning wife, Gwyneth Paltrow.
In a public display of affection rare for the publicity-averse couple, Martin leapt from the stage between songs and ran through the excited audience in search of his wife.
Once he found Paltrow he planted her with a smooch and then, just as quickly, transformed back into rocker mode and ran back to the stage to join his bandmates for their hit song "Clocks."
Video of the encounter between Martin, 35, and Paltrow, 39, who've been a couple since 2003, was posted to YouTube by a concertgoer. Paltrow appears just as surprised as the rest of the audience by her husband's affection, covering her face with her hands and then smiling broadly after the surprise kiss. Martin and Paltrow have two children, Apple, 8, and Moses, 6.
Martin later in the show dedicated the band's song "Yellow" to his "incredible wife Gwyneth," according to E! online.
The show of love evidently won Martin points with his bride as the couple was spotted continuing their PDA after the concert at the LIV nightclub at Miami's Fontainebleau Resort.
"Chris and Gwyneth drank champagne and she was all over him," a source told PEOPLE magazine. "They looked so much in love. Gwyneth danced all night."
Paltrow and Martin rarely walk the red carpet or appear together in public. Paltrow is often away on on movie sets while Martin is on tour.
According to Marie Claire magazine, the last time the two were photographed kissing in public was in a paparazzi shot of them in 2003.
The couple's Miami reunion may have been more than just spontaneous fun but a celebration of their new roots together. They already have homes in New York and London, and according to reports the pair recently purchased an 8,000-square-feet, six-bedroom mansion in Los Angeles for $10.45 million.