The cordial hour-long debate, broadcast nationally by several television networks, focused on Australia's worsening economic outlook as a mining boom fed by Chinese industrial demand cools.
Rudd has conceded that his centre-left Labor Party is the underdog in the September 7 elections, and successive opinion polls show that the conservative opposition coalition led by Abbott's Liberal Party is more popular.
But Labor takes comfort in Rudd outpolling Abbott as preferred prime minister.
"I think Rudd won the debate, but he needed to win it significantly in order to take back the momentum in the campaign," former Rudd adviser Lachlan Harris told Nine.
"He needs to win the campaign conclusively to win the election."
Abbott, a 55-year-old former Oxford University amateur boxer and Roman Catholic seminarian, claimed Rudd had "killed" the mining boom by imposing a 30 per cent tax on iron ore and coal mining companies' profits plus a tax on their carbon emissions last year.
Rudd, a Mandarin-speaking former Beijing diplomat who was deposed as prime minister by his own party in 2007 and then restored to power in June, accused Abbott of concealing spending cuts he would make as well as taxes he would increase to pay for his election promises if he wins.
Rudd is keen to have more televised debates, but Abbott has yet to commit to another.
Abbott introduced his passion for physical fitness to the campaign today by joining with 85,000 runners on the 14-kilometre Sydney to Bondi Beach annual fun run.
Rudd attended a Sunday church service in Canberra before announcing funding for a youth employment program in neighbouring Queanbeyan.
