Novak Djokovic (SRB) vs.  Stefanos Tsitsipas (GRE)
They were tied at one apiece coming into this match. Djokovic has been looking unstoppable as usual and Tsitsipas has been struggling to find his top form. If the Greek player wanted to beat the number one ranked player on the ATP Tour, he had to bring his best form.
Eleven years and seventy-three titles separate these two men; yet, it all becomes irrelevant when you step on court because anything is possible if you believe and can execute your plan. Tsitsipas had the belief because he was able to defeat the Serb before. However, things did not start off well for the Greek player, who was broken immediately and was never able to recover in the first set.
Tsitsipas Fights Back
Yet, the young Greek player has shown that he can hang with the best and shrugging off his disappointment at losing the first set, the twenty-one-year old elevated his game. Despite serving the higher percentage and winning more points on his second serve than his opponent; Djokovic still came out on the losing end because when it mattered most, Tsitsipas served better and won 3-6, 7-5, 6-3. Surprisingly, it was the Serb who cracked under the pressure in the second set; serving to force a tiebreaker, Djokovic squandered three game points and he never recovered from that mental lapse. On hard court, Djokovic had never lost a quarterfinal match after winning the first set, but there is always a first time for everything and today he suffered his first quarterfinal loss after winning the first set.
 Roger Federer (SUI) vs.  Alexander Zverev (GER)
Like the two previous players, these two were tied in their head-to-head; however, at three apiece. Interestingly, they had alternated their wins, with Zverev winning their last meeting. If things went according to history, Federer should have won this encounter. Yet, things often do not go as planned or expected on the tennis court.
Zverev Surprised Federer
Zverev came out focused and sharp, never allowing Federer to get into the first set. But Federer is a twenty-time major champion for a reason, he will fight and adjust his game accordingly. Thus, after dropping the first set, he broke Zverev immediately to take a 2-0 lead. Nevertheless, that lead was short lived as Zverev seems to have rediscovered his confidence late in this season and was playing some of his best tennis against the Swiss master. The German should have won this match in straight sets, he served for it at 6-5 and 40-0 up, but Federer would not relinquish the match without a fight.
Federer Fights Off Five Match Points
With his back against the wall, the Swiss player came up with some exquisite volleys to extend the set and the match. He fought off three match points to force a tiebreak, which he stole because the twenty-two-year-old German had two more match point opportunities in the breaker. However, the first was wiped away by a brilliant serve from Federer and the second was dashed on an unexpected backhand error from Zverev.
Zverev Not Discouraged
Zverev did not lose his belief despite losing a hard fought second set; he simply redoubled his effort in the third set and capitalized on his opportunity early in the third set. This time, there would be no mishaps; once he secured the break, he protected his serve and came away with the 6-3, 6-7(7), 6-3 victory. The tension was high in this match as Federer was assessed a point penalty, which seemed to get his fired up, but it was not enough to stop Zverev.
The other two semifinalists are Matteo Berrettini and Daniil Medvedev and they are both twenty-three-years old.
SOURCE OF IMAGE: main-serveandrally original (Alexander Zverev)