It was a bad day for Germany's Zverev siblings who lost semi-finals in different countries.
While Mischa was losing a tight three-setter at the Stuttgart International, younger brother Alexander was sent packing in straight sets in his last-four encounter in the Netherlands.
Mischa, seeded six, was beaten 6-7 (7-2) 7-6 (7-4) 7-5 by the experienced Spaniard Feliciano Lopez in a contest that lasted two hours and six minutes.
The opening two sets did not even yield a single break point - let alone a service break - which finally arrived in the 12th game of the decider.
Somehow, the 35-year-old Lopez managed to fashion the first break point of the tie by moving into a 40-15 advantage and sealing victory on his second match point.
On Sunday, the world No 33 from Toledo will chase a sixth ATP Tour title when he takes on the No 4 seeded Lucas Pouille who beat Benoit Paire in an all-French semi-final 7-6 (7-5) 7-5.
A victory for Lopez would bring him the third grass court success of his career, following victories at Eastbourne in 2013 and 2014.
And, around 340 miles away at the Ricoh Open in Rosmalen, 20-year-old Alexander - who is more than nine years younger than Mischa - lost 7-6 (7-5) 6-2 to Luxembourg's Gilles Muller.
Ultimately, it was the first set which proved decisive and ended in a tie-break after all 12 games went with serve.
From 4-2 up in the tie-break, the No 2 seed Alexander proceeded to lose five of the next six points, before being broken twice in the second set.
Muller, the No 4 seed, will now face Ivo Karlovic who won an all-Croatian semi-final against Marin Cilic.
The top seed Cilic did not even lose his serve during the three set marathon, which lasted 14 minutes short of three hours.
The 38-year-old Karlovic, who is the tallest player in the world's top 100, sent down 29 aces in his 7-6 (7-4) 5-7 7-6 (7-2) success.
And Sunday's match will have the oldest combined age for two finalists since Ken Rosewall (42) and Ile Nastase (30) met in the title match in Hong Kong in 1976.
In the women's event in the Netherlands, Russian Natalia Vikhlyantseva will meet Anett Kontaveit of Estonia in Sunday's final.
For those on the move, we will have Queen's Club, Halle and Wimbledon covered via our website skysports.com/tennis, our app for mobile devices and iPad, or follow our Twitter account @SkySportsTennis to join in the conversation. Who will win The All England Club titles this summer? Have your say...
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