Original: In 2001, Michael Schumacher made a one-off return to karts and competed against Hamilton along with other future F1 drivers Vitantonio Liuzzi and Nico Rosberg.
Simplified: In 2001, Michael Schumacher made a one-time return to karts and competed against Hamilton along with other future F1 drivers Vitantonio Liuzzi and Nico Rosberg.