The Omega Pharma-Lotto rider, who finished last year's Tour
de France in fifth place overall, attacked with less than five kilometers to go
to beat Spaniard Joaquim Rodriguez of the Katusha team after 144km from
Albertville.
Australian Cadel Evans finished third for the BMC team.
Kazah Alexandre Vinokourov (Astana) claimed the overall lead
while several Tour de France hopefuls, who use the Dauphine as a preparation
for next month's race, were unable to follow the pace in the final 10km ascent
to St Pierre de Chartreuse.
Van den Broeck broke away to catch Thomas Voeckler midway
through the climb and did not even look back when he went past the French
champion.
"It's my first big win, it's good for my morale,"
Van den Broeck told French TV channel France 3.
"I'm just back from five weeks training in altitude and
my legs were not very good." It was enough, though, to resist Rodriguez's
comeback as the Spaniard finished six seconds behind, with former world
champion Evans seven seconds off the pace.
Briton Bradley Wiggins took fourth place 11 seconds adrift
of Van den Broeck.
Italian Ivan Basso, the 2010 Giro champion, finished three
minutes nine seconds off the pace as he realized his build-up to the Tour would
be all but a stroll in the park.
Tuesday's stage is a 179km ride from Voiron to Lyon, ending
with a 1.4km climb at an average gradient of 4.8 percent.
The Criterium du Dauphine ends on Sunday, three weeks before
the start of the Tour de France on July 2.
