come to (someone's) rescue
To help someone in trouble. The phrase can be used for both serious and trivial situations. Thank goodness the lifeguard came to my rescue; otherwise, I might have drowned! Thanks for the notes! You totally came to my rescue after I missed so many classes.
come to (someone's or something's) rescue
to rescue or save someone or something. The paramedics came to our rescue at once. A big donor came to the college's rescue.