People watch Enrique Pena Nieto of the Institutional Revolutionary Party, PRI on a giant TV screen during the first televised presidential debate at Mexico City's main Zocalo plaza. On July 1, Mexico will hold presidential elections. (Eduardo Verdugo/AP)

Following a solid — if beaten and battered — performance at his first debate, the presidential front-runner from Mexico’s major opposition party, Enrique Peña Nieto, survived his biggest test yet, showing Mexican voters that the telegenic former governor could think on his feet and defend himself and his party against allegations of corruption and cronyism.

Going into Sunday night’s debate, analysts said that the only way for Peña Nieto’s three challengers to really shake his 20-point lead in the polls would be for the polished and well-scripted candidate to fumble in a spectacular way — to draw a blank on an answer, for example, as Texas Gov. Rick Perry did in a Republican presidential debate when trying to list three federal agencies he would eliminate.

It didn’t happen. Peña Nieto, of the Institutional Revolutionary Party, or PRI, survived, even as he was called a liar and a fraud by Josefina Vazquez Mota of the ruling conservative National Action Party (PAN) and leftist Andres Manuel Lopez Obrador from the Democratic Revolutionary Party (PRD).

“Why do the people who really control the country want Peña Nieto to be president?” Lopez Obrador asked during the two-hour televised debate. “The answer is obvious — they want to continue with their policies of pillage.”

Vazquez Mota, who if elected would be Mexico’s first female president, held up an Economist magazine profile of Peña Nieto that she said contained allegations that he had reported misleading figures about his crime-fighting successes while governor of the state of Mexico.

“There are two ways of lying,” Vazquez Mota said. “One is not telling the truth, and the other is making up numbers.”

In another demonstration, Lopez Obrador held up a photograph of Peña Nieto with former president Carlos Salinas de Gortari of the PRI party, an unpopular figure whose administration was tainted by charges of corruption.

“Who is Enrique Peña Nieto, really?” Lopez Obrador asked. At another point, Lopez Obrador said a return to power by the PRI — which ruled Mexico for more than 70 years, until 2000 — would bring “pure lies and pure insecurity” to Mexico.

While defending himself against allegations of wrongdoing, Peña Nieto got in some punches of his own. “They’re coming with knives sharpened,” he said of his challengers.

Speaking of the current administration of President Felipe Calderon and his PAN party, Peña Nieto described the country’s economic performance as the worst in 80 years.

“I propose changing fear for hope,” Peña Nieto said. “I propose changing Mexico.”

Jorge Chabat, a professor at the International Center for Investigations, in an online opinion forum compared the debate to a soccer match, with Peña Nieto playing goalie and his opponents kicking balls at him, trying to score.

Chabat said Vazquez Mota fired shots, warning viewers that the states controlled by the PRI party were beset by corruption, murder, debt, violence and “femicide” — the killing of women.

More than 50,000 people have died in five years of drug violence in Mexico, where soldiers are deployed in the most violent cities. Mexico’s economy sputtered along through the global turndown and is headed toward small to moderate growth.

Speaking directly to the cameras and not to one another, in a television studio without an audience, the four candidates were asked about security and the economy from a list of published questions.

The debate was aired on two minor TV channels and had to compete with the playoffs for the Mexican soccer league, which dominated the viewership.

Apart from attacking one another, the candidates offered some proposals.

Peña Nieto promised to increase access to Mexico’s state-supported health-care system. “Today, only four in 10 Mexicans have access to social security. My commitment is to raise that protection to 10 in 10 Mexicans,” he said.

Vazquez Mota, speaking of the two television companies that dominate Mexican broadcasting, said the nation needed a break from the duopolies. “Mexico requires not just a third, fourth, fifth or sixth TV broadcaster. Mexico requires as many broadcasters  as technology allows and as consumers need. Only in competition the citizens will have power again.”

Lopez Obrador promised to lower the price of fuel sold by the state petroleum company, Pemex, to stimulate economic development for small businesses. He also said he would insist on a corruption-free national police force and would gradually pull the military off the streets.

The most recent poll, released before the debate by newspaper El Universal, showed Peña Nieto with 39 percent support, down from 41 percent in April. Vazquez Mota drew 22 percent, while Lopez Obrador followed in third place at 17 percent.

A fourth candidate, Gabriel Quadri of the New Alliance Party, also took part in the debate, calling himself the citizen’s candidate. The New Alliance Party is a creation of the powerful teachers union. Quadri, who is polling in the low single digits, offered the most specific answers to the debate questions, rather than simply attacking Peña Nieto.

A second debate is scheduled for June 10. The presidential election is July 1.