Playing almost exclusively with each other throughout their 25-year careers, the Bryans captured a professional era record 118 titles, including 16 Grand Slam titles, 39 ATP Masters 1000s, and the ATP Finals title four times.
Rafael Nadal will now likely require a victory over in-form Stefanos Tsitsipas on Friday to reach the semi-finals. The Greek booked his place in the last four by thrashing Alexander Zverev 6-3 6-2 latter.
Roger Federer broke Berrettini to open the second set, but had to overcome a slight wobble at 4-3. Federer trailed 15-40 in that game and had to save three break points in total before holding with an ace.
The Spaniard, who took his major haul to 19 this year, has a patchy record at the tournament. He has never won the title, appeared only eight times despite qualifying on 15 occasions and on his last visit, in 2017, withdrew injured.
The ITF had taken the decision on November 4, paying heed to AITA's repeated requests for a neutral venue, which prompted the PTF's to challenge the move. In response, the ITF reached out to AITA on Monday.
The PTF President Salim Saifullah said the event-free opening of the Kartarpur corridor is a clear indicator that despite the ongoing diplomatic tensions, it is possible to host the Indian tennis team in Islamabad.