Los Angeles Superior Court Judge Brenda Penny made the decision after hearing the testimony from the 44-year-old ex-manager and from the singer's father James Spears, who has taken care of his daughter's money and affairs via a court-ordered conservatorship for nearly 11 years.
Penny rejected arguments from Lutfi's attorney Marc Gans, calling the former manager's testimony evasive and extending the temporary restraining order she first issued on May 8.
Gans said outside the court that they are considering an appeal.
The singer's father conceded under questioning from Gans that he does not have a peaceful relationship with his daughter.
"Me and my daughter's relationship has always been strained," James said.
However, in further testimony that Penny said she found credible, James testified that Lutfi, who was close to Spears in 2007 and 2008 and served as her manager for a brief period, has been a "predator" to his family for more than a decade and whose harassment has recently resumed.
"I was worried that he was trying to take down the conservatorship. I was very angry. I was worried that we were right back in 2008," James said from the stand.
James and his lawyers stated and Penny seemed to agree that Lutfi has attempted to provoke fans who have used the social media hashtag #Free Britney to criticise the control James and the court have had over the 37-year-old pop star for the past 11 years.
Lutfi's Twitter account consists of most of the posts critical of Spears' circumstances and those surrounding her. However, Gans argued that none of the statements were made directly to any individual or could be considered harassment.
He also stated that Lutfi has made no direct contact with Spears and suggested that her father and his lawyers were not speaking for her and had provided no evidence that she had in any way been harmed by the ex-manager's statements.
The singer was not present in court and she has made very less public comments on the conservatorship.
In a testimony that Penny struck from the record, the former manager said that Spears had reached out to him several times through the years to complain about her father's control over her.
"She wanted help to get out of this situation," Lutfi said.
The judge also shut down most of the questions by Gans directed towards James. The questions were on his daughter's mental state and tried to establish that the derogatory online statements Lutfi made about James' use of alcohol were true.
Lutfi admitted that he had contacted the singer's mother Lynne Spears, and the artist's brother-in-law James Watson via texts and phone calls, and sent Lynne money that was subsequently returned.
Lutfi testified that he sent the money "just like numerous other fans did" because Lynne had "liked" Instagram posts that suggested she was in need of money and that she should be in charge of her daughter's affairs instead of her ex-husband James.
Gans also argued that tweets from Lutfi, including one that simply said "Raise hell," were far too vague to be considered as harassment. Penny disagreed with Gans, citing that tweet in her decision as illegal incitement.
The proceedings were a continuation of a hearing that began on May 28 and had been closed to the media and the rest of the public. However, Penny, who also oversees Spears' conservatorship case, kept the courtroom open on Thursday.
The Spears family has frequently fought the ex-manager in court, starting with a restraining order they received against him in 2009.
Britney's family has long blamed the ex-manager for taking the singer down the bad path that ended with her mental breakdown in 2008.