The Sun is powered by a chain of nuclear reactions (the so-called”proton-proton cycle”) which burn hydrogen and produce Helium. In these reactions also neutrinos are emitted. Unlike photons, which take approximately 100 thousand years to travel from the Sun’s core to its surface, neutrinos cross the solar matter in few seconds and reach Earth in 8 minutes, thus providing a real-time picture of the Sun interior. The Borexino experiment has been devoted for over 7 years to the difficult hunt for elusive solar neutrinos. Thanks to the unprecedented radiopurity of the detector and its large mass, Borexino has been able to study most of the components of the solar neutrino spectrum. In this talk I will focus on the latest result published by the experiment, which consists in the first direct observation of the solar neutrinos from the primary reaction p + p ? d +e+ + ?e which is responsible for most of the solar luminosity.