After the court was emptied, the two players hung around, unsure what was going on. Kukushkin received treatment on his leg and Struff chewed on a banana.
But not long after play was suspended, a conversation with a Wimbledon official saw both players pack up their bags and leave the court.
About 40 minutes after play was suspended, spectators started filtering back into their seats and play resumed at 5pm local time — approximately 50 minutes after the drama brought the match to a standstill.
Struff's clash with Kukushkin was the second match on Court 12 after American Alison Riske defeated Belinda Bencic to book a fourth round meeting with Aussie Ash Barty.
Barty is scheduled to play the final match on Court 12 tonight when she teams up with Victoria Azarenka for their second round doubles match against Swede Rebecca Peterson and Tamara Zidansek.
Earlier in the day, Serena Williams warmed up for her opening mixed doubles match by reaching the fourth round in singles. The seven-time singles champion, who has teamed up with Andy Murray, beat Julia Goerges for the second year in a row, eliminating the 18th-seeded German 6-3 6-4.
"I wanted to play mixed because I've played not even 15 matches, or just about 15 matches, so far this year," Williams said. "So I thought it could really help me.
"There's such a buzz going around about me and Andy that I've gotten nervous now, I feel like I might have a little bit performance anxiety.
"I hope I can live up to the hype."
Williams beat Goerges in the semi-finals last year before losing to Angelique Kerber in the final. She will next face world No. 30 Carla Suarez Navarro, who made it to the fourth round at Wimbledon for the third time by beating unseeded American Lauren Davis 6-3 6-3.
Murray, who is limited to playing doubles at the moment as he returns from an operation for a hip replacement, lost in the men's doubles tournament on Saturday.
Top-ranked Ash Barty also made it through to the second week in singles, winning her 15th straight match. The French Open champion beat Harriet Dart 6-1 6-1 and will next face Alison Riske of the United States.
Two-time Wimbledon champion Petra Kvitova, who a week ago wasn't even sure if she could hold a racquet in her left hand, reached the fourth round at the grass-court grand slam for the first time since her last title at the All England Club in 2014, beating Magda Linette 6-3 6-2 on No. 2 Court.
Kvitova, seeded sixth, broke her opponent three times while never giving Linette a chance to break back even once.
The Czech will next face Johanna Konta, who reached the Wimbledon semi-finals in 2017. The 19th-seed beat 2017 US Open champion Sloane Stephens 3-6 6-4 6-1, her fourth victory over the American in four matches this year. No. 21 Elise Mertens and Barbora Strycova also advanced.
In the men's draw, two-time Wimbledon champion Rafael Nadal defeated two-time semi-finalist Jo-Wilfried Tsonga 6-2 6-3 6-2.
Nadal beat Tsonga on Centre Court in a match that wasn't nearly as taxing as his second-round victory over Nick Kyrgios. He never faced a break point, broke Tsonga five times, and served out the match with an ace.
Also, No. 5 Kei Nishikori, 2017 semi-finalist Sam Querrey and Tennys Sandgren all reached the fourth round.
