Astronomers using the W. M. Keck Observatory have identified the first known quasar acting as a gravitational lens that magnifies an even more distant galaxy. Hundreds of cases of gravitationally lensed distant quasars with foreground galaxies are known. But, until now, the reverse process - a background galaxy being lensed by a massive foreground quasar - had never been detected. The discovery may provide astronomers with a new technique to study quasars.