Preston North End came out 3-2 winners in an entertaining clash away from home against high-flying Norwich City.
Josh Sargent scored just two minutes in for the Canaries, but PNE picked themselves back up and Riis scored his second in as many games by heading home in the 25th minute.
The Dane’s second of the afternoon then came shortly into the second period and, after being pegged back by Gabriel Sara, a Troy Parrott effort took a huge deflection to beat Tim Krul at his near post to win the game for North End.
It was an unchanged starting XI from the midweek victory over West Brom, but things didn’t get off to a good start for PNE, with Ben Whiteman sliding in but losing the ball to Sargent, and the American cut inside to fire past Freddie Woodman inside the opening two minutes.
Sargent could have doubled his tally on eight minutes, but this time was denied by Woodman, who was also required to keep out Aaron Ramsey soon after.
Play did settle down from that point with PNE able to enjoy some possession, creating chances for both Riis and Sean Maguire, before Teemu Pukki chipped a big chance just wide for the hosts.
North End then found an equaliser on 25 minutes, with Robbie Brady sending a great cross into the box for striker Riis to head home for his third of the campaign.
There was a contentious moment on the half-hour mark, as Sam Byram went in high on the leg of skipper Alan Browne, but his punishment was only a yellow card.
PNE almost found themselves going into the break ahead after a fantastic team move saw Fernández slip the ball through to Maguire, who in turn pulled it back for Riis, and Byram produced a crucial interception to stop the ball from reaching the Dane.
That was the last action for both Byram and Maguire, who were both replaced at the break, with Troy Parrott the man to come on for Ryan Lowe’s side.
Seven minutes into the half, PNE found themselves in front. Fernández nipped in ahead of Max Aarons to start a rapid break, and the Manchester United loanee found Riis in space on the far side, and the striker kept his cool to slot home.
Woodman was then required at the other end to frustrate Sargent, sticking out a strong hand to save his volley, while Tim Krul kept out a powerful Parrott strike.
PNE’s ‘keeper was beaten 15 minutes from time by substitute Sara, who slammed home to find the top corner on the end of Pukki’s cutback.
North End had a quick response, though, with substitute Parrott putting the ball back into the box and a huge deflection helped it make its way past Krul at his near post.
Woodman needed to tip a late Onel Hernandez effort over the bar, before the Canaries then had a late goal ruled out for a foul inside the box, and PNE left East Anglia with the points.
Norwich City line-up: Krul; Aarons, Omobamidele, Hanley, Byram (Sara, 45); Núñez (Dowell, 72), Gibbs (Hernandez, 81), Ramsey (Sinani, 59), McClean; Pukki, Sargent. Subs not used: Gunn, Gibson, Hugill, Hernandez.
PNE line-up: Woodman; Storey, Lindsay, Cunningham (Hughes, 79); Browne, Whiteman, McCann (Johnson, 82), Brady (Woodburn, 67), Fernández; Riis, Maguire (Parrott, 45 (Ledson, 82)). Subs not used: Cornell, Diaby.
Attendance: 26,062 (PNE fans: TBC).
Referee: Mr D Whitestone.