Millar won the Paris-Nice prologue to give him a good start

The Scot, who is not a specialist climber, showed great stamina to finish 14th in the tough 169.5km leg between Maurs and Mende.

Promising Spanish rider Alberto Contador won the stage in four hours seven minutes and 26 seconds.

Davide Rebellin took second and the overall lead with Millar 42secs behind.

Results from the fourth stage:

1. Alberto Contador (Spa) Discovery 4hr 7min 26 sec
2. Davide Rebellin (Ita) + 2sec
3. David Lopez (Spa) + 12
4. Cadel Evans (Aus) + 13
5. Tadej Valjavec (Slo) + 17
6. Frank Schleck (Lux) + 28
7. Sebastien Joly (Fra) + 33
8. Levi Leipheimer (US) "
9. Thomas Lovkvist (Swe) "
10. Franco Pellizotti (Ita) + 40