John Vasilopoulos and Nick Tragaras stood before an assembly line of egg sandwiches. Mr. Tragaras slid the eggs and bacon from the griddle onto the buns as Mr. Vasilopoulos followed to wrap and stack.

It was a familiar rhythm for the owners of Cup & Saucer, a diner on the eastern edge of Manhattan’s Chinatown. But on Monday afternoon, after more than 70 years, the clink of metal spatulas flipping eggs and bacon will quiet for the last time as Cup & Saucer closes its doors.

“We really care about every customer who comes in; we get involved with them,” Mr. Vasilopoulos, 55, said over the weekend from behind the doughnut display as the narrow corridor of counter space filled up.

From that perch, he and Mr. Tragaras, 52, have watched the neighborhood ebb and flow over their 30 years of ownership. The family jewelry and wholesale shops that once dominated the area are long gone, and more expensive restaurants and bars have moved in. This time, Mr. Vasilopoulos and Mr. Tragaras said, the rent increase was too steep for Cup & Saucer.