Ricciardo finishes third, under half a second from second-placed Lewis Hamilton – the closest finish so far this year.
Wear and degradation minimal around the demanding streets of Monte Carlo, without compromising performance.
In the championship, Fernando Alonso is still third on 61 points, half the total of the leader Rosberg.
Valtteri stopped on track following an issue related to the Power Unit.
Christian Horner: "We closed down the gap to the Mercedes at the end and got very close to Lewis."
The team has now taken five consecutive one-two finishes, for just the third time a team has achieved this in F1 history.
Nico Rosberg wins the 2014 Monaco Grand Prix.
"They looked very strong in the first test in Jerez, but they haven't been able to deliver on track. Looking from where we are it looks as if they have gone backwards," said Wolff.
Felipe Massa: "I'am disappointed and tomorrow is going to be a challenge but with this car points are still possible."
Fernando Alonso:** “Today’s result encapsulates the state of play this weekend and it’s more or less what we expected..."
Jean-Eric Vergne: "If we can put everything together, I’m confident we can finish in the points with both cars."
Transcript from the press conference following the controversial end to qualifying at Monaco.
Nico Rosberg and Lewis Hamilton qualified in first and second places respectively for the Monaco Grand Prix today.
Sergio Perez: "Although it’s good to be in the top ten, I’m feeling a bit disappointed not to be higher up the grid."
Christian Horner: “Locking out the second row of the grid is a very positive result."
McLaren will start the Monaco Grand Prix in eighth (Kevin Magnussen) and 12th (Jenson Button).
The team is now concentrating on getting the best out of this situation tomorrow.
Did Nico Rosberg deliberately cause a local yellow in an effort to impede the qualifying lap of teammate Lewis Hamilton?
Mercedes will hold a press conference in the Monaco paddock on Saturday morning, attended by title sponsor Petronas, Daimler chairman Dieter Zetsche, team boss Toto Wolff and drivers Rosberg and Lewis Hamilton.
Intermediate tyre proves its versatility once more.
The Sauber F1 Team engineers were not able to complete the planned programme, but were still able to make a little progress.
An overcast day of practice in Monaco saw Sahara Force India end both sessions inside the top ten as Nico Hulkenberg and Sergio Perez started preparations for Sunday’s Grand Prix.
Valtteri Bottas: "Overall I am feeling positive and I'm looking forward to getting back in the car."
Eric Boullier: "“The possibility of an unpredictable race is a welcome one”
The Ferrari duo completed 81 laps of the street circuit, with Fernando Alonso doing the lion’s share of 46.