According to The Mirror, the duo grew jealous of the attention and advances of fellow clubbers.
Ronson, who was DJing at the Chinawhite venue, apparently had girls' knickers and telephone numbers handed to her in the DJ booth, which upset Lohan.
Later, Ronson was apparently angered by a girl "stroking Lindsay's arm and giggling with her".
"Sam shot daggers at the girl, who left immediately," said a source.
However, the duo reconciled their differences at the end of the evening when Sam performed a lapdance for her lover.
A witness commented: "They went in for a full-on tongue sandwich, their hands all over each other. Nobody knew where to look."