Jetstar, the budget unit of Qantas Airways, makes its first Singapore-Melbourne flight today, marking the beginning of its challenge to Singapore Airlines on long-haul routes.

The carrier sold 210 tickets for the 8:50 p.m. flight, including 24 in business class, Simone Pregellio, a spokeswoman, said today. The low-fare airline will operate the daily seven-hour flight using an Airbus SAS A330-200 that can carry as many as 303 passengers.

Jetstar may base as many as four A330s in Singapore by the end of next year, as it adds flights to Auckland in March and possibly services to north Asia and southern Europe later in 2011, Jetstar Asia Chief Executive Officer Chong Phit Lian said today. The carrier is touting fares 30% cheaper than rivals as it seeks to lure travellers from full-service carriers.

“Competition will increase and this will put some pressure on Singapore Air,” said Kelvin Lau, a Hong Kong-based analyst at Daiwa Institute of Research, who has an ‘outperform’ rating on SIA. “There will always be people who will want the cheapest fares.”