The 50km (31 mile) HK Ultramarathon saw competitors cover the same stretch of road 25 times.
Nestor Wong won the event in 3:24:20 and defended the course, saying it helped to hear the cheering crowds.
An ultramarathon is defined as any race above the standard marathon distance.
Ahead of the event, local runners criticised the course.
"It will be boring and very difficult, if not dizzy, for the runners who will have to do 25 laps of the same stretch of road," Thomas Kiprotich told the South China Morning Post.
"I don't mind monotonous courses, but this is a bit extreme monotony for my tastes," Michelle Lowry added.
Kwan Kee, chairman of the Hong Kong Amateur Athletic Association and one of the race organisers, conceded that the course was "quite boring".
But he told AFP spectator access would help: "It was great that we could secure this course in the heart of the city... land in Hong Kong is very limited."

The England Lions batsman ended on 117 as the hosts made 255-6 in 92 overs in their pursuit of overhauling Kent for second spot and £43,000 prize money.
Skipper Daryl Mitchell weighed in with 67 as he completed 1,000 first-class runs for the fourth time in his career.
Ben Cotton picked up 3-46for Derbyshire on his firstteam recall.
The visitors have not managed a Championship away victory and are hoping to avoid going an entire season without a win on the road for the first time since 2008.
Worcestershire batsman Joe Clarke told BBC Hereford & Worcester:
"It was quite difficult out there. The pitch is very slow. Once you get in, it is a lot easier but to start with it is very tough.
"It has got a little bit more pace in it now but this morning it was very slow and credit to Daryl Mitchell. He did a fantastic job in getting us through that period.
"It meant a lot to get a hundred because we've been struggling a little bit with the bat.  In the last few weeks, we haven't been getting the scores we'd have liked and to be there at the end is very pleasing.
Derbyshire bowler Ben Cotton told BBC Radio Derby:
"It was nice to take a couple of wickets on my return. It took me a while to settle in for the first five or six overs, then I found a nice rhythm and took the wickets we needed.
"You've just got to put as many balls as you can in the right area and hopefully there is enough there to take an edge or get an lbw.
"Tony Palladino and Tom Milnes started well after tea and put some pressure on them and due to their hard work I took a wicket and managed to get another near the end as well."

A post-mortem examination found that Mr Hunter, from Coulsdon in south London, died from a single gunshot wound at the private event in Headley, near Epsom.
Two other people were also injured in the shooting shortly after 02:30 BST on Monday.
A 36-year-old woman was shot in the leg and taken to hospital while another man was treated for minor shoulder wounds.
A man from London, 38, who was arrested on suspicion of murder and attempted murder remains in custody.
A woman, 30, arrested on suspicion of assisting an offender has been released on conditional bail until September, police said.
Specialist divers have been searching a village pond for the gun used in the shooting, while forensic teams are continuing a detailed examination of the address in Church Lane.
More than 400 people were at the party at the hired house.
The annual event had been organised by reggae dancehall artist Jason White and his girlfriend Summerlyn Farquharson.
He told BBC Newsbeat they used seven security staff with metal detectors to check all the guests as they arrived.
Det Ch Insp Paul Rymarz, from the Surrey and Sussex Major Crime Team, said: "This was a shocking incident where a man lost his life and we are determined to bring those responsible to justice."
He said police intended to speak to everyone who was at the party, and appealed for anyone not already contacted to come forward.
"This incident has understandably sent shockwaves through the Headley community and we are working with our Safer Neighbourhood Team colleagues to update and reassure residents," he said.
"We do not believe there is any ongoing risk to Headley residents."
Hundreds of runners have competed in Hong Kong's first inner-city ultramarathon, despite organisers describing it as "quite boring".
[NEXT_CONCEPT]
Joe Clarke made his fifth County Championship century of the summer as Worcestershire batted out the opening day against Derbyshire at New Road.
[NEXT_CONCEPT]
A man who died during a shooting at a pool party in Surrey has been named as 34-year-old Ricardo Hunter.