Iran's president, Mahmoud Ahmadinejad, has now traded bare-knuckled verbal blows with both of his reformist challengers in American-style live televised debates that have electrified the atmosphere before Thursday's watershed elections. On Saturday night he and Mehdi Karrubi, a septuagenarian former speaker of parliament, accused each other of corruption, scorned each other's foreign policy and clashed over Iran's troubled economy. Each swatted aside his opponent's allegations as self-serving attempts to win votes.
Mr Ahmadinejad, 52, was left reeling against the ropes by an early body-blow from the white-bearded reformist, who is the only cleric among the four presidential contenders. Mr Karrubi mocked the president for claiming that a halo-like, celestial green light had descended on him when he addressed the UN General Assembly four years ago. World leaders were supposedly so transfixed by Mr Ahmadinejad that they sat unblinking - literally - for nearly 30 minutes as he spoke. The president's opponents have long used the tale to portray him as a hallucinating zealot who appears to believe he is on a divine mission.
In response, a visibly winded Mr Ahmadinejad simply spluttered that the New York episode was untrue. However, a video clip of the president recounting his mystical experience to a leading ayatollah, Adollah Javadi-Amoli, has been circulated on Iranian websites. It took some time after the "halo" jibe for Mr Ahmadinejad - who sported a dark striped suit rather than his trademark, man-of-the-people cotton bomber jacket - to regain his quick-witted pugnacity and recover his smile that often resembles a smirk. But while he chuckled at his opponent's barbs he was never as self-confident as he was in a similarly fiery encounter last Wednesday with Mir-Hossein Mousavi, a moderate candidate who is Mr Ahmadinejad's main threat to securing a second four-year term.
So toxic were their exchanges that the supreme leader, Ayatollah Ali Khamenei, ordered the candidates to watch their words in the unprecedented series of gruelling, 90-minute televised debates where each hopeful went head-to-head with his rivals Dismayed at the unedifying spectacle of prominent insiders of Iran's Islamic system exposing alleged fraud and corruption, Ayatollah Khamenei declared: "Candidates themselves should know that they should not let their campaigning cause unrest in the country."
Mr Mousavi's high-profile wife, Zahra Rahnavard, and a powerful former president, Akbar Hashemi Rafsanjani, have threatened legal action against Mr Ahmadinejad for making unsubstantiated personal attacks on them during his debate with Mr Mousavi. Why Ayatollah Khamenei authorised the televised debates is unclear, but it is likely he viewed them as one way to counter voter apathy. Iranian leaders regard a big turnout at the polls as a public endorsement of Iran's unique, quasi-democratic Islamic system. A large turnout, however, will favour the two reformist hopefuls whose supporters are more difficult to galvanise than Mr Ahmadinejad's well-organised, hardline followers. Ayatollah Khamenei, who seems to have tacitly endorsed Mr Ahmadinejad's candidacy, may mistakenly have calculated that the incumbent would floor his opponents with early knockout punches.
Instead, the debates have given the two reformist hopefuls an opportunity to lambast the performance of Mr Ahmadinejad's government on national television. Before the 2005 election, there was just one televised debate, involving all candidates, followed by another between the two front runners who made it to the second round. Prior to the serial debates, Mr Mousavi and Mr Karrubi had criticised state-run television for giving saturation coverage to Mr Ahmadinejad while they were largely ignored. Now the four men are also getting equal airtime for their individual campaign TV advertisements and radio broadcasts.
Despite the supreme leader's undeclared support, Mr Ahmadinejad astutely has attempted to use the debates to portray himself as an underdog in an election race that he says is not between four candidates, but one that is pitting "three people against one". Ayatollah Khamenei's call for more gentlemanly debates was largely ignored in Saturday's often fiery encounter. "Lying is the worst sin in Islam," Mr Karrubi declared as he accused Mr Ahmadinejad of dishonesty for painting a rosy picture of Iran's inflation-hit economy, which is viewed as the incumbent's Achilles' heel.
Mr Ahmadinejad used a dazzling array of colourful statistical charts to claim that he was managing the economy well, with inflation allegedly dropping and unemployment rates comparing favourably with those in the West. Dismissing the president's statistics, Mr Karrubi said: "I have been working in the parliament for 16 years all the figures that you have given are contradictory to the ones we have seen over the years."
On foreign policy, Mr Karrubi echoed criticism by Mr Mousavi that the president has alienated many countries and said his statements doubting the Holocaust had played into the hands of Iran's enemies. Mr Karrubi quoted a chief of Israel's Mossad spy agency enthusing that Mr Ahmadinejad had been a "blessing" for Israel. The reformist also took his opponent to task for befriending Hugo Chavez, even though the Venezuelan president had been a supporter of the late Iraqi dictator, Saddam Hussein. And Mr Karrubi scoffed that the president, known for his lurid anti-American rhetoric, had written letters to both George W Bush, the former US president, and his successor, Barack Obama, without receiving a reply.
Here, Mr Ahmadinejad appeared on more comfortable ground. He defended the letters as a "kind of public diplomacy" and insisted his foreign policy had strengthened Iran's global standing and served the Islamic Republic's interests. Iran, he argued, had received nothing for suspending uranium enrichment during the presidency of his reformist predecessor, Mohammad Khatami, when Washington had also branded the Islamic Republic part of an "axis of evil".
Today, Mr Ahmadinejad argued, Washington is seeking reconciliation with the Muslim world and reaching out to Iran. "Four years ago, Mr Bush used to speak about toppling Iran, but now Mr Obama is saying nothing can be achieved without Iran and is calling for Iran's co-operation. How come you [Mr Mousavi] are denying the nation's achievements?" Analysts believe Saturday's debate could win Mr Karrubi more votes at the president's expense, although this is most likely to benefit Mr Mousavi, who is well ahead of his fellow reformist in Iran's unpredictable opinion polls.
Mr Karrubi's supporters were delighted with his performance. Thousands rallied outside the television studios during the debate, which they followed on large screens, chanting slogans and cheering wildly whenever their man bashed the president. email@example.com * With additional reporting by Maryam Sinaee in Tehran