Alexander Zverev, Stefanos Tsitsipas stunned on day one at Wimbledon

Alexander Zverev and Stefanos Tsitsipas, the supposed next generation of men’s tennis, were shock casualties in the first round at Wimbledon.

Novak Djokovic’s potential path to the final looks even clearer after the young guns, both in the defending champion’s half of the draw, fired blanks.

Sixth seed Zverev went down in four sets to qualifier Jiri Vesely, the world number 124.

The 22-year-old slipped at a crucial moment to give away two match points, and then netted the first as Czech Vesely celebrated a surprise 4-6 6-3 6-2 7-5 triumph.

Zverev, who has endured a poor year so far, admitted his confidence has taken a battering and alluded to issues off the court.

“When I get to the important moments – and I had five or six break points in the fourth set alone – I can’t take any of those,” he said.

“I’m down one break point myself and he takes it immediately, where I miss an easy volley. I didn’t lose this match on tennis. It’s just my confidence is below zero right now.

“The last two days, I would say (were) very rough for me personally. I’m not going to get into details, but I’m just saying. I have to fix that to play well on the court.”

Around 20 minutes later Tsitsipas, having saved two match points in the fourth set, succumbed to the third as he was turfed out 6-4 3-6 6-4 6-7 (8) 6-3 by Italian Thomas Fabbiano.

Zverev and Tsitsipas are supposedly at the head of the pack attempting to chase down Djokovic, Roger Federer and Rafael Nadal. On this evidence the big three are still a long way in the lead.

Tsitsipas said: “We’ve seen players my age, many years ago – I would like to name Rafa, Roger – seemed very mature and professional what they were doing. They had consistency from a young age. They always did well, tournament by tournament, without major drops or inconsistency.

“Something that we as the Next Gen players lack, including myself, is this consistency week by week. It’s a week-by-week problem basically, that we cannot adjust to that.”

Djokovic was the first of the gilded trio to flex his muscles at this year’s championships, the Serbian opening proceedings on Centre Court against Philipp Kohlschreiber.

The world number one double-faulted the opening point on his way to dropping serve in the first game.

But order was soon restored, Djokovic, breaking straight back and then wearing his German opponent down in a 6-3 7-5 6-3 win.

It was a maiden victory for Djokovic since he added former Wimbledon champion Goran Ivanisevic to his coaching team.

Last year’s runner-up Kevin Anderson eased into round two after a straight-sets win over Pierre-Hugues Herbert.

The big-serving South African, who 12 months ago shocked Federer in the quarter-final and then came through a marathon five-setter against John Isner, won 6-3 6-4 6-2.

Frenchman Herbert can now at least turn his full attention to the doubles, where he has linked up with Andy Murray.

Three-time grand-slam winner Stan Wawrinka made short work of Belgian Ruben Bemelmans, the Swiss roaring to a 6-3 6-2 6-2 victory in less than an hour and a half.

Wild card Feliciano Lopez carried on from where he left off after his singles and doubles win at Queen’s Club, beating Marcos Giron in straight sets to get his 70th consecutive grand slam off to a flying start.

In the all-Canadian affair on Court 12 – on Canada Day – teenager Felix Auger-Aliassime won his first grand slam match against Vasek Pospisil.

The 18-year-old, seeded 19 after a remarkable rise up the rankings in the past year, dropped the first set but recovered to win 5-7 6-2 6-4 6-3.

Ivo Karlovic is still going strong at 40, beating Italian Andrea Arnaboldi 6-4 6-4 7-6 (4).

The Croatian, the oldest man to play in the singles event since Ken Rosewall in 1975, will face Fabbiano in round two.