Five for five! It's still early...ish, but the specter of tiebreaks will start rearing its head soon if the draws continue.
But not yet. Fabiano Caruana and Magnus Carlsen tested the Rossolimo for a third time, and Caruana varied first by playing 4.0-0 instead of 4.Bxc6. The play was sharp, and while Caruana evidently hoped to surprise Carlsen it seems that the champion was well-prepared. A first semi-critical moment came when Caruana played 12.Qe2, as this left the bounds of safety he would have enjoyed with 12.cxd6. 13.Qc4 was also a bit risky, and soon he was the one who needed to demonstrate equality.
After an inaccuracy or two Carlsen was pressing, and for him the key moment was move 20, when he faced a choice between 20...b5, playing for control, and 20...Kb6, looking to activate the king. After approximately 22 minutes he chose the latter, and this let Caruana escape. The challenger played perfectly after this, and used Black's active king as a source for counterplay. After a forcing sequence they reached a dead drawn endgame, and called it a day after 34 moves - just like game 4. (Curiously, games 2 and 3 both finished in 49 moves. It's unlikely though that any subsequent game will pair up with game 1's 115 moves.)
Here's the game, with light annotations. Game 6 is tomorrow, and in both game 6 and game 7 Carlsen will have the white pieces.