`Proud` Michelle Obama congratulates Serena Williams over successful 2015 season

Washington : First Lady Michelle Obama is proud of Serena Williams even as she lost in the US Open women’s semi-final.

The American President’s wife took to twitter to share her feeling after Serena suffered a devastating loss of her career, saying “So proud of you, @SerenaWilliams. What you did this year was amazing. -mo #USOpen2015,” HollywoodLife.com reports.

Earlier, Roberta Vinci crushed the world number one’s hope of completing a calendar grand slam by reaching the women’s singles US Open final for the first time in her career.

The unseeded Italian produced a resilient performance as she fought back to overcome the 21-time Grand Slam champion 2-6, 6-4, 6-4 in a pulsating semi-final clash at Flushing Meadows.

American tennis star Serena was hoping to secure the first calendar grand slam since Steffi Graff in 1988. (ANI)