The KTM rider has finished fourth and third in the last two editions and has got off to a good start this year winning in a time of seven minutes and 51 seconds.
Yamaha's Frans Verhoeven of the Netherlands was second and there were encouraging signs for Honda in their first Dakar for 24 years with another Chilean Pablo Quintanilla in third.
Defending champion Cyril Despres was fifth.
Stage One result
1 Francisco Lopez Contardo (CHI) 7:51
2 Frans Verhoeven (NED) +01
3 Pablo Quintanilla (CHI) +05
4 Patricio Cabrera (CHI) +11
5 Cyril Despres (FRA) +13
6 David Casteu (FRA) +15
7 Ruben Faria (POR) +19
8 Javier Pizzolito (ARG) +21
9 Pal Anders Ullevalseter (NOR) +26
10 Joan Barreda Bort (ESP) +29