McGregor won Outstanding Lead Actor in a Limited or Anthology Series or Movie for his role in Halston.
"Mary, I love you so much. I love you so much," the 50-year-old gushed. "I’m gonna take this home and show it to our beautiful little boy, Laurie."
"And to my beautiful girls who I know are watching, Clara, Jamyan, Esther and Anouk, I said I would say hello to you too," he added.
"I just want to thank our crew first of all because like so many people have said tonight, we shot through the pandemic in New York City and through everybody’s professionalism and passion, kept us all safe. And so we couldn’t have done it without you," he said during the speech. "Ryan Murphy, thanks for championing Halston and bringing it to Netflix. Thank you to Netflix."
This is McGregor's fourth time being nominated for an Emmy — and his first win.
In June, it emerged that Trainspotting alum and Winstead had welcomed their first child together.
"Met my little brother looking like a pirate. I recommend! Welcome to the family little Laurie 🥰," McGregor's 19-year-old daughter Esther wrote on Instagram with a photo of herself holding the baby.
"Welcome to the world little brother ❤️ congratulations to my Dad & Mary — this is the greatest gift," McGregor's 25-year-old daughter Clara gushed on Instagram at the time.
Clara had previously spoken ill of Winstead after the actress became embroiled in a scandal for being photographed cozying up to McGregor while he was still married to Eve Mavrakis, who he shares his daughters.
Clara later told The Times that she was "angry and upset" when she slammed the Kate actress and "it wasn’t the most mature way to go about things."
McGregor and the 36-year-old are believed to have first met in 2016 on the set of Fargo. The actress split from her husband Riley Stearns in May 2017. Months later, the Birds of Prey star was spotted kissing McGregor, who was still married to Mavrakis at the time.
McGregor filed for divorce in January 2018 and asked to be declared single in November of that year. Their divorce was finalized last year.
McGregor and Winstead "kept the pregnancy under wraps at first, but when Clara and her sisters found out about it, that really changed things, and little by little the ill will subsided," an OK! insider spilled.
The Moulin Rouge! actor "didn’t try to force the kids into accepting Mary and let them come around in their own time," the insider explained. "Now Clara and her sisters are constantly visiting, because they love spending time with Laurie and want to get to know Mary better. This baby was the missing link everyone needed for the bonding to happen!"