TORONTO -- Bill Murray says the Toronto International Film Festival premiere of his new comedy "St. Vincent" brought him to tears.

Seated next to co-stars Naomi Watts, Melissa McCarthy, Chris O'Dowd and young Jaeden Lieberher as well as writer-director Ted Melfi at a Sunday morning media gathering, Murray recalled the surprisingly deep emotional reaction elicited by the film's debut this week.

"I think we were all moved by the response of the audience," said Murray, dressed rather conservatively in a navy sweater vest, an oxford shirt and slacks. "We've all sort of seen the movie at one stage or another on the way to being finished ... and the final work that Ted did on it, he really cleaned it up. It really motored. It really rolled.

"It affected me. ... I think we all got emotional from it. I was crying. And I realized that if the lights come up and I'm crying, my career is finished. But it was like that."

While the screening left Murray in tears, he left Sunday's press assemblage in stitches -- gleefully tearing into his director, unfortunate journalists and even his (absent) actor brother Brian Doyle Murray, with his sharpened-to-a-stake sardonic wit.

He wrested control of the conference early, when Watts -- resplendent in a cream-coloured blouse -- was discussing the work that went into locating her prostitute character's impenetrable Russian dialect. Soon, Murray sighed audibly and let his eyes roll skyward.

"Are you bored?" Watts asked him, smilingly distracted.

Murray nodded before purring off-mike: "Just keep talking."

A moment later, the moderator directed a question to Murray about drawing a "through-line" through his impressive filmography -- "St. Vincent," after all, represents another film where Murray interacts with a much-younger co-star (this time in the pre-adolescent Lieberher).

"I'm still stunned by Naomi's efforts to acquire an accent. She's working on her American accent right now," he deadpanned to resounding laughter.

"I also want to say that was some of the most polite morning applause I've ever heard," he said, turning his attention to the audience of journalists. "Let's get our baseline understanding here -- that was much appreciated."

Finally, he deigned to answer the question. Sort of.

"Your question is stultifying. I'm frozen. ... (But) you had a question and I'm sure you meant it," he added wryly. "If there's a through-line in my work I'm glad that you have found it.

"I'm sorry. It's early. It's a long day ahead of us. You get to go home or to a bar or something but we have to work. We're going to take it easy here."

He certainly didn't take it easy on Melfi. A few days after drolly commenting that Melfi was "nobody" during a Q-and-A with Toronto moviegoers, he managed to fire a few more arrows at the first-time filmmaker.

First, he chastised the moderator for beginning the session by directing a question to Melfi, cracking: "(I) deeply regret that you began with Ted because it put us off on the wrong foot."

Later, Lieberher (cutely clad in a bowtie) said that the most challenging part of his role was a four-page speech in the script that he had to deliver to an auditorium of onlookers.

"What kind of a director gives a 10-year-old a four-page speech? A sadist. A sadist and a monster," Murray interjected. "And then shoots 51 angles of tracking shots? Only a first-time director would do something so foolish.

"Do they have child labour laws?"

To prepare for the scene, meanwhile, Lieberher said Murray guided him in meditation. Asked what specific kind of meditation it was, Lieberher replied: "It wasn't serious meditation."

"It worked, didn't it? Come on," Murray replied.

"We just put our heads down on chairs and then closed our eyes," Lieberher explained.

The film casts Lieberher as the impressionable next-door neighbour of Murray's titular crank, a gleefully bad influence who nevertheless looks after the boy (reluctantly and for a price) while his mother (McCarthy) toils away at a demanding job.

Although Murray complained about the early-hour nature of the conference, once he got warmed up he didn't seem to want to stop. When a moderator warned the gathering that the next question would be the last, Murray asked for a "couple more," lamenting: "We woke up for this."

Specifically, he wanted the journalists to spread the wealth to his castmates, who hadn't received as much attention. But when one of the scribes then polled the rest of the cast for "Bill Murray stories," he rolled his eyes and once again steered the situation.

"That was nice of you. Really generous of you. Can we have this woman removed?" he declared to peals of laughter. "Let's try another question. You're on probation."

After the conference was over, Murray ventured into the crowd to find the journalist, muss her hair and take a photo together.

"Do you know how to hurt feelings or what?" Murray asked her with a smile.

Given the comic credentials of the starry film's cast, however, each did find a time to shine. O'Dowd, the Irish star of "Bridesmaids" and "Girls," jumped in when a journalist asked Melfi why he was wearing a New York Yankees hat and not one memorializing his hometown Brooklyn Dodgers.

"That was the journalist from Vogue," O'Dowd cracked, taking a similarly irreverent approach to a question about his sharing scenes with kids in the film.

"I think one thing I've learned in my years is that kids are idiots," he replied. "I've never met a kid I liked."

McCarthy, meanwhile, was queried on whether she had a traumatic experience with a bad neighbour.

"I'm still in litigation," she replied.

"I lived next door to peacocks," Murray then contributed. "And when peacocks mate in the summer, they go all night long and it sounds like crying babies. It's the most disturbing thing. You bolt awake in the night."

Really, the actors were content to put on a show -- a fact which Murray laid bare after, of all things, a question about the 30th anniversary of his blockbuster comedy "Ghostbusters."

"Well, 'Ghostbusters' paid for my children's college education, which means that they can flunk out much earlier than they would have if they had to pay their own way," he replied. "That was such a big experience for me. It was more than I could handle. I had to leave town, move away, get out of the country.

"Back then, movies, we didn't take them so seriously. It wasn't such a serious business. We used to do them for fun and because we liked the work. Back then we really had a lot of fun and working with that group -- Harold Ramis and Danny (Aykroyd) and Ivan (Reitman), Annie Potts and (Rick) Moranis -- these were all just people you'd love to be trapped with for a couple months. Really, true hilarity all the time.

"You could feel free to try anything you wanted to do and perform for each other," he added. "Just perform for each other all the time. And when you do that, it's a gas.

"We're performing for each other this morning right here. You're just stuck with us. We're amusing the hell out of ourselves."