Djokovic – who is bidding to match Federer’s men’s record of eight Wimbledon titles and claim an outright record 25th major title – was the overwhelming favourite against Safiullin, but found his latest test far from straightforward.
Safiullin, a former quarter-finalist, was in tears after his stunning third-round victory over rising star Joao Fonseca, having struggled with an injury he feared he would never fully recover from six months ago.
The free-hitting Russian, 28, was rewarded for his persistence when he took his first set in four meetings with former world number one Djokovic to prolong the contest beyond the three-hour mark.
But, just as he did against Arthur Rinderknech in the previous round, Djokovic captured the fourth set to seal victory and set up a last-eight meeting with Canadian third seed Felix Auger-Aliassime or Spain’s Alejandro Davidovich Fokina.
Safiullin appeared full of belief as he began his bid for a monumental upset, responding to Djokovic’s immediate break of serve by winning five of the next six games.
But he could not convert that positive position, faltering as he served for the set at 5-3 and eventually coming up short in the tie-break.
Despite the 125-place ranking gap, Safiullin had continued to prove a nuisance in the second set until he presented Djokovic with an opening in the sixth game, and eventually conceded a fourth break point.
Having to come through three consecutive five-set matches since the final round of qualifying to arrive here began to take its toll as Safiullin required a medical timeout for a left-leg problem during the third set.
But he successfully managed that issue to capture his first set in four tour-level meetings with Djokovic, who landed only 57% of his first serves and took out his frustration on a ball after Safiullin took a sixth break point for a 4-2 lead.
Despite that incident, which was booed by the crowd, Djokovic quickly reset and launched a decisive fourth-set response, breaking to love in the second game as Safiullin’s challenge began to fade.
Lifting over a closing drop shot to serve out victory to love, Djokovic embraced Safiullin at the net – and there was deserved warm applause for the spirited qualifier’s performance as his superb run, in which he also ousted 12th seed Andrey Rublev, came to an end.
Djokovic has now been taken to four sets in three of his four wins at this year’s championships, but remains in the hunt for history after reaching his 17th Wimbledon quarter-final.
