Sen. Susan Collins, the Maine Republican everyone had been waiting on to announce her vote, built up her support for Kavanaugh in a roughly 45-minute speech before concluding, "Mr. President, I will vote to confirm Judge Kavanaugh".
The vote tally is 51-49, while the fate of full confirmation, which could be as early as Saturday, remains unclear.
Senator Collins ended hopes she would side with Democrats in the final vote, telling fellow senators she did not believe the "charges can fairly prevent Judge Kavanaugh from serving on the court".
Republican Senator Lisa Murkowski voted against advancing Mr Kavanaugh, and Senator Joe Manchin was the only Democrat to join the opposition in voting "Yes". She told reporters on Friday that Kavanaugh is "a good man" but maybe "not the right man for the court at this time".
A total of 164 people were arrested according to U.S. Capitol Police. "Nothing can be further from the truth", she said.
"I've never considered a president's party or identity" in confirming a Supreme Court justice, Collins said, adding that she confirmed President Obama's Supreme Court picks Justice Elena Kagan and Justice Sonia Sotomayor.
Flake, like Collins, believed that the FBI investigation, which did not corroborate the sexual assault allegations, was thorough.
Collins said Christine Blasey Ford's dramatic testimony to the Senate Judiciary Committee last week describing Kavanaugh's alleged 1982 assault on her were "sincere, painful and compelling".
Kavanaugh protesters paid by billionaire Soros
Hundreds more demonstrated outside the Supreme Court and inside the Senate Hart Office Building on Thursday. Among the women who have shared their stories of surviving sexual assault were two who accosted Sen.
"On average, any woman in the United States Senate, whether they're on Judiciary or any other committee, probably work harder than the average man", he said.
That means Kavanaugh could be an associate justice of the U.S. Supreme Court by the end of the weekend.
Ms Murkowski of Alaska, a state that also voted pro-Trump in 2016, has been undecided on Judge Kavanaugh throughout the hearings.
The vote caps a contest fought against the backdrop of the #MeToo movement and President Donald Trump's unyielding support of his Supreme Court nominee. But I value and respect where my colleagues have come down from in their support for the judge, and I think we're at a place where we need to begin thinking about the credibility and integrity of our institutions. On that same day, two of the three swing Republican senators - Maine's Susan Collins and Arizona's Jeff Flake - praised the thoroughness of the recently concluded FBI investigation into allegations of sexual assault against Kavanaugh.
Senate Democratic leader Chuck Schumer of NY called the fight "a sorry epilogue to the brazen theft of Justice Scalia's seat".
"The allegations fail to meet the "more likely than not" standard", Collins said of the accusations against Kavanaugh.
When Trump nominated Kavanaugh in July, Democrats leapt to oppose him, saying that past statements and opinions showed he'd be a threat to the Roe v. Wade case that assured the right to abortion.
The outcome, telegraphed Friday when the final undeclared senators revealed their views, was devoid of the shocks that had come nearly daily since Christine Blasey Ford said last month that an inebriated Kavanaugh tried to rape her at a 1982 high school get-together.