On a day that low scores were the norm, Drysdale shot a record 10-under 62.
"I played really well last year and then in practice here on Tuesday and I managed to continue that today," said Drysdale. "That's the lowest score I have had on (the tour) so it feels pretty good. This would be up there with the best rounds that I have ever had on (the tour). In fact, it's probably the best I have ever had."
Carlos Rodiles of Spain is second after shooting 9-under 63. South Africa's James Kingston and Francisco Valera of Spain are tied for third at 7-under 65.
Defending champion Mikael Lundberg of Sweden opened at 4-under 68, and is in a group of nine players tied for 12th place.