Two-time winner on European Tour, Chowrasia, who lost his card on the Tour last year, had five birdies, two bogeys and one double bogey.
The other three Indians in the field, Jeev Milkha Singh, Shiv Kapur and Gaganjeet Bhullar carded two-over 73 each to be tied 43rd. Thomas Bjorn, the veteran star, called 'Big Dane', was among three players to card a 5-under 66 and he shares the lead after the opening round.
Bjorn and Aguilar each have a win this season, while Dredge is seeking his first victory since the 2006 Omega European Masters.
Thorbjorn Olesen carded a 2-under 69 to sit alone in fourth place. Tied with Chowrasia in tied fifth were Peter Lawrie, Nicolas Colsaerts, Sihwan Kim, Daniel Gaunt, Chowrasia, Andrew Marshall, Andreas Harto, Roope Kakko and Philip Archer.
