Actress Katie Holmes shocked runners at the New York Marathon yesterday when she joined them enroute, unannounced.

Sporting suitable jogging attire with the number F127, the Dawsons Creek star was virtually unrecognizable on the 26.2 mile race route.

The 28-year-old – who completed the marathon with a final time of five hours, 29 minutes and 58 seconds - was later swarmed by photographers as she crossed the finishing line where husband Tom Cruise was waiting for her, holding the couple’s daughter Suri.

Holmes was overheard giggling "Here I am baby, signed, sealed, delivered, I'm yours" as she ran into her husbands arms.

Cruise later gushed, telling the press: "She's very inspired. She trained for three months."

Former cyclist Lance Armstrong also participated in the race with a time of two hours, 46 minutes and 42 seconds.

To see pictures of Katie participating in the NYC Marathon, click here!