Five years after he returned to stand-up comedy, Robin Williams appears to be attempting another return to the stage. At least, that’s what it looked like last night when Williams launched into his first of two sold-out last-minute performances at the Comedy Connection in Boston.

The reasoning? Williams is the star attraction Friday at the Yankee Dental convention at Hynes Convention Center. The dentists are paying $100-$175 to see him there. On Saturday, people will pay $225-$275 to see Williams perform at the Borgata Hotel Casino & Spa in Atlantic City. No wonder, then, that the comic might want to brush up on his stand-up skills before having fans pay a pretty price just to hear him. They should get their money’s worth. Right?

So what did Boston fans (who’ll see him again at 10 p.m. tonight) get for their $25 in the intimate Comedy Connection setting?

For one thing, 98 minutes of pure Robin Williams (for better or worse, depending upon your viewpoint within the comedy community). The theme of his wildly scattered riffing? Everything old is new again. And everything new is up for ranting.

Dressed simply in a black short-sleeve T-shirt (with monster skull face) and black jeans, he opened with about a half-hour of material that couldn’t have been more topical if he were a late-night TV talk-show host. "I’m here as part of ‘The Departed’ tour!" he quipped, before launching into typical Robin-style rapid-fire ad-libs on audience members in the front row. After a few words on a fur coat, he acknowledged: "That’s old joke number one!" He managed to get in thoughts on John Kerry’s announcement yesterday that he would not run for president, weaved into the Kennedys and the British royal family, the Big Dig and its failure — "Even the Egyptians are saying: ‘You should’ve gotten Jews!’" — a reference to his recent trip to rehab, the State of the Union address, Britney Spears, the Miss USA scandals and Donald Trump and his "feud" with Rosie, iPods, Tony Blair, Rumsfeld, Cheney, Condi, Kissinger and Ahnold, Mel Gibson — which led to Williams’ thoughts on portraying Jesus on film. Peter Lorre as Judas? Funny. Christopher Walken as Jesus? Hack. Brando as Pilate with Joe Pesci and Robert DeNiro as disciples? Also sorta hack. Then more on Gov. Ahnold, immigration and gay marriage.

Williams didn’t seem to grasp that San Francisco isn’t the only place that gay marriage is a big issue. Perhaps his team — in addition to his two-man sound crew, he had multiple people in the corner recording his show and taking notes — would fill him in in time for tonight’s show.

Yes, Williams pulled out his old impersonations of John Wayne and Jimmy Stewart, but updated them as gay cowboys. He also had plenty to say about the Catholic Church and the Popes, showing off his interpretations of the half-dead Pope, the Nazi Pope, an African Pope, an African-American Pope (Pope Diddy?), and a Brazilian Pope.

Then he got personal for a while, talking about his lifelong battle with alcohol. He introduced warning signs you may be an alcoholic (with apologies — mine, not his — to Foxworthy), then expanded his talk to include tobacco, Coca-Cola (the old version, with cocaine!), opium and heroin, constructing a flashback sequence to act-out the discoveries of various drugs that ended with a play on "playing with my Wii!" Williams had some words to say about technology, too, with a bit I remember from his 2002-2003 tour, along with bits on the problems of directory assistance, cars with talking GPS systems and hybrid cars, which led to NASCAR.

Williams ended his first act (1 hour, 23 minutes) with a routine about intelligent design that can best be described as one elongated dick joke with a Bush punchline.

A standing ovation brought Williams back onstage almost immediately for 15 more minutes of seemingly random riffing. "This is wild," he said. "I haven’t been back in a long time. Not since Good Will Hunting." He even took requests. And in his crowd work, he couldn’t have known that local comics Micah Sherman and Joe List were among his front-row targets. Fortunately for everyone, they didn’t take his bait. That would’ve been awkward. So would’ve taking pictures or using my camera-phone for ill gains. So this is what you get. For now.