The 4th seed Daniil Medvedev earned the 17th consecutive victory on Saturday in Melbourne, beating Filip Krajinovic 6-3, 6-3, 4-6, 3-6, 6-0 in three hours and six minutes. It was Daniil's first five-setter triumph in a career after losing the previous six marathons, struggling to find his usual pace in sets three and four and sending his coach Gilles Cervara after an argument in the fourth set.
Confident about his player, Cervara made the right move, as Daniil started to play better after that to bring the decider home with a bagel and secure the place in the last 16. Medvedev had 52 winners and 44 unforced errors, controlling the pace in sets he won and converting seven out of 18 break opportunities, three of those in the encounter's final part.
The Russian landed a backhand winner in the first game for an instant break and settled into a fine rhythm behind the initial shot. Daniil wrapped up the set with another break at 5-3 after 30 minutes, looking good ahead of set number two.
Krajinovic wasted three break chances in set number two and fell 4-2 behind to push the rival in front. Serving for the set at 5-3, Medvedev fended off two break chances and opened two sets to love advantage when Filip netted a backhand.
They traded breaks early in the third set, and it was the Serb who stood strong and delivered a break in game ten for 6-4.
Daniil Medvedev and Casper Ruud are through to the last 16 in Melbourne.
Krajinovic survived a challenging opening game in set number four and grabbed a break at 2-1, serving well and taking the set 6-3 to force a decider.
Hitting a reset button, Daniil landed an ace down the T line in the fifth set's opening game and broke with a forehand crosscourt winner to move 2-0 in front. The Russian secured the third game with an ace and painted a forehand winner a few minutes later for a 4-0 lead.
Marching towards the finish line, Daniil sealed the deal when Filip netted a forehand in game six to reach the last 16 and celebrate his first victory in five sets. Twenty-four years after his father reached the Melbourne fourth round, Casper Ruud repeated that with a 6-1, 5-7, 6-4, 6-4 triumph over Radu Albot in two hours and 58 minutes.
Casper lost serve twice and delivered five breaks to control the scoreboard and earn another notable victory.