The 29-year-old royal redhead and his 25-year-old blond girlfriend watched as England faced Wales at a rugby game at Twickenham during a Six Nations match.
Harry was casually dressed and showed his team spirit with an England white polo shirt and occasionally slipped on his aviators, while Cressida wore a white blouse, gold hoop earrings and sunglasses at the sporting event.
The beautiful couple was good luck for England because they defeated Wales by a score of 29-18.
France, Ireland, Italy and Scotland are also participating in the championship.
Cressida joined Harry on Friday at the inaugural U.K. event benefitting Free the Children, an international charity working to engage and empower young people to work together towards ending poverty. He gave a speech to 12,000 students and admitted to being "incredibly nervous" to address his young audience, then quipped, "If you were expecting Harry Styles, I apologize. And no, I'm not going to sing."
Earlier in the week, Harry had dinner at The Ivy with Cressida and her brother-in-law Sam Branson.
A source said at the time the pair "seemed happy and relaxed" during their meal with Sam, who married Cressida's half-sister Isabella Calthourpe last year, and that the group all seemed "casual and friendly."