Stan Wawrinka rolled back the years for a glorious victory over Casper Ruud at the Swiss Indoors, joining fellow veteran Andy Murray in putting on a show in Basel.
Former world number one Murray pulled off a remarkable win over Russian Roman Safiullin, winning five games in a row from 4-1 behind in the final set.
But that was just a tease for the excitement that followed, as Wawrinka, who like Murray won three grand slam titles in his prime, felled second seed Ruud in straight sets.
The 37-year-old Swiss delighted his home crowd with a 6-4 6-4 victory over this season's French Open and US Open runner-up, serving nine aces as he defied a world ranking of 194th to produce some of his old magic.
Murray has fallen away from the elite ,too, but at 49th in the world he is not far away from rejoining that pack, although defeat looked to be beckoning against Safiullin.
The 35-year-old Scot fist-pumped with relief at recovering the break of serve that Safiullin snatched early in the decider, and Murray hit a service winner on his second match point to seal a 6-7 (5-7) 6-3 6-4 success.
The victory for two-time Wimbledon winner Murray took him to 26 wins this season, the most he has had in a single campaign since pulling off an astounding 78 victories in 2016, the year he won at the All England Club for a second time, landed a second Olympic gold medal and finished top of the rankings.
Murray said of his win: "As the match went on, I started to dictate a few more points and served better."
Quoted on the ATP website, he added: "I changed the way I was returning a little bit, and when I did that, I was able to create a few more opportunities and frustrate him a little bit."
Pablo Carreno Busta scored a 6-2 6-1 win against Argentinian Sebastian Baez, with Alex Molcan, Dominic Stricker and Botic van de Zandschulp also advancing to the last-16 stage.
At the Vienna Open, Murray's fellow British players Cameron Norrie and Dan Evans both went through to the second round, Norrie beating Argentina's Pedro Cachin 3-6 6-2 7-6 (7-1) and Evans fending off Germany's Oscar Otte 6-4 7-6 (7-3).
Canadian left-hander Denis Shapovalov beat Austrian wildcard Jurij Rodionov, but the home crowd had something to celebrate when former US Open champion Dominic Thiem continued his resurgence by eking out a 2-6 7-6 (7-2) 7-6 (8-6) victory against American Tommy Paul, saving two match points.