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Gavin Newsom, right, is sworn in as the 49th lieutenant governor of California by his father, William A. Newsom, left, as his wife, Jennifer Siebel Newsom, looks on

Gavin Newsom was sworn into office as lieutenant governor on Monday, closing the most dramatic week of his seven years as mayor of San Francisco and opening a new chapter in his career on the statewide stage.

At approximately 1:24 p.m., with his hand on a bible held by his wife, Jennifer Siebel Newsom, and his gaze fixed upon his father, the former Judge William A. Newsom, who administered the oath, Newsom officially relinquished his position in San Francisco — and ended one of the more remarkable political spectacles the state has seen.

Newsom’s decision to delay his swearing in by a week in order to influence the selection of his successor drew criticism from his foes in San Francisco and posed unresolved questions about the legality of the move.

But Newsom departed having achieved his objectives, after installing a successor he supported: City Administrator Edwin M. Lee, who attended the swearing-in ceremony and received enthusiastic applause. In his final 24 hours in office, Mayor Newsom also made a shock appointment, picking San Francisco police Chief George Gascón to replace Kamala D. Harris, now the attorney general, as district attorney.

“Gavin Christopher Newsom, we are delighted you are here at last,” Bill Lockyer, the state treasurer, said archly in his introductory remarks for Newsom, drawing laughs from the chamber.

In contrast to Gov. Jerry Brown, who delivered a no-frills inaugural address last week that underlined a sober commitment to tackling the state’s budget shortfall, Newsom swept into Sacramento with swagger, style and some soaring rhetoric.

The lieutenant governor’s office is largely bereft of any legislative powers or a budget (Newsom’s staff will be less than a half-dozen people), but Newsom will sit on several committees and be expected to represent the state in trips around the country and the globe.

Still, the former mayor (and former gubernatorial candidate) seemed to dive into his new statewide role with gusto.

Justin Sullivan/Getty Images

Gavin Newsom places his hand on a bible held by his wife, Jennifer Siebel Newsom, as he is sworn in as the 49th lieutenant governor of California Jan. 10, 2011

At times, he shifted into a folksy accent, dropping his g's and flattening his y's.

“All right!” Newsom exclaimed after he took his oath, and proceeded to rattle off a list of officials in the audience whom he called friends and allies — including Harris and Darrell Steinberg, the state Senate’s president pro tem — as he vowed to “add value to the debate” in Sacramento.

He then delivered a 24-minute speech from the chamber’s pit, calling on the Legislature to embrace innovation and green technology in order to lead the state out of its fiscal crisis.

“I didn’t come up here to try to support a process where we could fail more efficiently. It’s time for an order-of-magnitude change, because we simply can’t afford the status quo,” Newsom said. “We’ve got a big pothole in California and we don’t got that much gravel to fill it.”

As the new chairman of the state Commission for Economic Development, Newsom promised to draw upon his experience as the leader of San Francisco. His city, Newsom said, led the country in its progressive legislation and spurred economic development by pursuing pro-environment incentives.

“We created a green-collar economy,” he said. “We created a framework for green-collar jobs that I’ll put up against any small city in the country.”

While Newsom’s speech was largely devoid of legislative details, it touched some rhetorical highs, as Newsom spoke of making California — which he called the “Coast of Dreams” — great again.

“That’s the magic of this remarkable state, that pioneering spirit where people came from all over the world for riches and new beginnings,” he said. “I’m proud of our past, I’m excited about the opportunity of the present, but I’m absolutely secure in my belief that the best is yet to come.”

Correction: A previous version of this article incorrectly identified Bill Lockyer as the former insurance commissioner. He is currently the state treasurer, and has previously been the state attorney general and a state legislator.