"Well, thank God," he told ABCNews.com late Monday, after learning about his daughter's decision. "I think it's a healthy decision that she take a break and relax and pursue her own career and her own goals. What they had was very toxic. It had become very toxic."
"Lindsay doesn't need to keep following Samantha around," Michael Lohan said. "She needs to sit down with her parents. She needs the support of both of us to help her along. Lindsay's an emotional person. I want her to get on with her life in the right direction and a healthy way."
On Monday afternoon, the 22-year-old actress confirmed to E! News that reports of her breakup with Ronson were true, saying "We are taking a brief break so I can focus on myself."
Tuesday, Sgt. Lincoln Hoshino of the Beverly Hills police department told ABCNews.com that members of Ronson's family came in Monday to request information about obtaining a restraining order, presumably against Lohan. He said they were directed to Santa Monica superior court.
Breakup rumors have been swirling around Lindsay Lohan and Ronson for weeks. This weekend, she was reportedly barred from entering a party Ronson was DJ-ing at West Hollywood's Bar Marmont. But as recently as Wednesday, Lindsay Lohan told E! News that the couple hadn't broken up.
ABCNews.com's e-mails to Lindsay Lohan's publicist for comment were not returned late Monday night.
After an arrest warrant issued against Lindsay Lohan in March, her dad spoke out about her declining well-being and star power. That arrest warrant, which Lindsay Lohan's lawyer said was issued because of a "misunderstanding" regarding the actress' probation, was later dismissed by a Beverly Hills, Calif., judge.
"I'm still adamant about the fact that Samantha got Lindsay in a very vulnerable state and played on that," Michael Lohan told ABCNews.com in March. "Every time Lindsay shows up at one of Samantha's gigs, there's a fight. There's always some kind of big problem."
"If Samantha really loved Lindsay, she wouldn't have had her in that atmosphere," he said. "She's using Lindsay to further her own career."
Can Breaking Up With Ronson Save Lohan's Career?
She has also strayed from the movie industry. Her last film, the 2007 horror flick "I Know Who Killed Me," earned her two Razzie Awards for worst actress. She does, however, retain ad campaigns with brands including Fornarina jeans and Sevin Nyne spray tan.
It doesn't look like she'll rebound with her upcoming film "Labor Pains," in which she plays a woman who fakes a pregnancy to save herself from unemployment.
Instead of hitting the big screen, "Labor Pains" will premiere on ABC Family in July and come out on DVD a month later.
Lindsay Lohan, who recently told E! News that she wants to have her "own charity, do work overseas [and] be in Oscar-nominated films," once boasted one of the most promising careers in modern-day Hollywood.
She charmed as a child star in Disney's 1998 remake of "The Parent Trap" and won critical acclaim in 2004's "Mean Girls."
Her father hopes her breakup with Ronson will get her career back on track and he's ditching his New York digs for Los Angeles this week to help make that happen.
"I'm going to clear my schedule and get out there," he told ABCNews.com Monday. "I know she wants me out there."