Julia Stiles got Michelle Williams' OK before Heath Ledger dance tribute

Julia Stiles asked Heath Ledger's former partner Michelle Williams for permission before honouring him with a routine on Dancing with the Stars this week.

During Tuesday's Dedication Night episode, Stiles and her professional dance partner, Ezra Sosa, performed a contemporary routine to Frankie Valli's Can't Take My Eyes Off You, which Ledger famously sang in their 1999 teen movie 10 Things I Hate About You.

After the performance, Stiles revealed that she ran the idea past fellow actress Williams, the mother of Ledger's 20-year-old daughter.

"I did ask Michelle if this was OK and she said yes," she told Extra TV.

Ledger and Williams began dating in 2004 after meeting on the set of Brokeback Mountain, and they welcomed their daughter Matilda, who turns 21 later this month, the following year. The pair split in 2007, and Ledger died of an accidental overdose in January 2008.

In her dance, Stiles incorporated some of his moves from the singing scene into her routine. At the end, an image of the actors on the set of the film appeared on the screen as audio of her character's poem played.

The Save the Last Dance actress placed a single rose on a set of steps before holding hands with her 10 Things I Hate About You co-stars - Joseph Gordon-Levitt, Gabrielle Union, Larisa Oleynik, Andrew Keegan, and Susan May Pratt - on the dance floor.

Explaining why she wanted them involved, Stiles said, "When we decided we were going to do the dedication, we needed to have somebody here to sort of represent the movie and represent Heath. I was like, 'It has to be the whole cast, it can't just be one person, it's got to be everybody.'"

In a separate interview with Entertainment Tonight, she noted that her co-star David Krumholtz "wanted to be here", but he was busy working on a show in New York.

Krumholtz confirmed the reason for his absence in a social media video and added, "I would have loved, loved, loved to have been there. Everyone looked so amazing. Julia's tribute to my dear friend who I miss every single day was amazing and stunning, and I'm so proud of her."