Two first-time quarterfinalists battled it out to open play on Rod Laver Arena with 14th seed Stefanos Tsitsipas claiming a hard-fought 7-5, 4-6, 6-4, 7-6 (3) victory over 22nd seed Roberto Bautista Agut to reach the semifinals of a major for the first time.
The 20-year old Greek, coming off an upset victory over six-time Aussie Open champion Roger Federer in the Round of 16, fired 22 aces and hit 68 winners in the three hour, 15 minute contest to become the youngest man to reach the last four at Melbourne Park in 16 years.
Tsitsipas rallies from a break down to win first set
Things got off to a rough start for the Greek as he was unable to return a deep forehand by the Spaniard and after duffing an overhead on break point, Bautista Agut had an early break advantage.
Tsitsipas had his first break chance in the fourth game, but Bautista Agut was able to stave off the 20-year old's challenge. Bringing up another chance in the eighth game, the 14th seed took advantage, throwing up a defensive lob that resulted in the 22nd just missing a forehand wide.
Wuth Tsitsipas ahead 6-5, he set up double set point with a forehand winner. After Bautista Agut saved the first chance with a forehand volley, the Spaniard was unable to save the second, dumping a backhand into the net to hand the set to the 20-year old.
Bautista Agut hangs on to early break to even match
Again, Bautista Agut struck early. He was handed two break points in the third game of the second set after Tsitsipas mishit a forehand and was on top after playing a smart slice off of a drop shot by the Greek for a 2-1 lead.
Neither man was pushed again on serve until the ninth game when Tsitsipas served to stay in the set. Pushed to deuce twice, the Greek won a backhand-to-backhand exchange to set up game point and a lob to close out the game.
Bautista Agut stepped up to serve for the set and he raced out to a 30-0 lead. He set up double set point using his biggest weapon, the forehand, to draw an error from the Greek and closed it out with an unreturnable serve to level the match at one set all.
Tsitsipas takes final two sets to reach semifinals
Tsitsipas escaped deuce in the opening game of the third set and was in trouble in the fifth game, falling behind 0-40. After saving the first, the Greek was behind, Bautista Agut stinging a series of forehands, eventually the third one giving him a 3-2 advantage.
The Greek was threatening the Spaniard's serve, holding a pair of break points in the eighth game. After saving both, Bautista Agut faced a third after netting a forehand and after chasing down a drop shot, was errant again from that wing to surrender his lead.
Tsitsipas held to 30 to take a 5-4 advantage and held three set points on the Bautista Agut serve. After failing to convert on the first two, he played a brilliant slice backhand up the line in response to the Spaniard's drop shot to take a two sets to one lead.
The fourth set was a masterclass in serving as both players barely lost points, five love holds in the first seven games. Finally, with Tsitsipas leading 6-5, he was presented a match point after a Bautista Agut double-faulted.
The Spaniard staved off elimination by winning a 20-ball rally culminating in a forehand just inside the line for a winner. Bautista Agut forced a tiebreaker, but was down a minibreak after Tsitsipas hit an overhead smash for a winner to go ahead 2-0.
From that point forward, five straight minibreaks occurred with Tsitsipas eventually in front 5-2. Back-to-back unreturnable serves closed out the win for the Greek and sent him to his first career Grand Slam semifinal against 2009 Aussie Open champion Rafael Nadal.