London - Mark Cavendish's hopes of competing at the Rio Olympics were dealt a blow as he finished sixth in the omnium at the Track Cycling World Championships in London on Saturday.
Cavendish had been set a target of a top three finish by British Cycling coaches if he is to win selection to their Rio squad, but poor showings in the time trial and individual pursuit saw him finish outside the medal places as Fernando Gaviria Rendon took gold.
"I wanted to test it. I don't know if I am going," Cavendish said of his Olympic hopes.
"But I really wanted to test myself against the best riders.
"Hopefully I did enough for selection. I don't know. We are incredibly lucky with GB that we have a group of strong guys to go to the Olympic Games. We have got an absolute load of riches."
Colombian Gaviria successfully defended his title in the tightest possible finish in front of 8,000 fans at the Lee Valley VeloPark.
The Etixx-Quick-Step road rider edged out two rivals in an amazing finish to the six-discipline event with a masterful tactical display in the points race.
With the lead changing hands multiple times over the 160 laps of the deciding points race, the top three positions were not decided until the 16th and final sprint of the 40-kilometre race as the 21-year-old Gaviria came over the line ahead of Roger Kluge of Germany and Australian Glenn O'Shea.
That trio were tied on 191 points with the countback being determined by their respective finishing positions on that final sprint.
"It was an epic battle," said Gaviria. "All the riders were very strong and I'm just pleased I managed to defend my title.
"People say I'm crazy, I don't think about the race too much, I just go with the flow and try not to make many childish mistakes that would be normal for someone of my age."
O'Shea ultimately paid the price for a disastrous showing in the individual pursuit event in which he could only come 17th, but the Australian is hopeful of turning his bronze medal into gold at the Rio Olympics.
"I had one bad event and that was out of character for me," said O'Shea. "But there are no excuses there. You can say it cost me a gold medal but I was close and one bad event out of six isn't bad.
"The last two World Championships I've been on the podium and I'll put my hand up for the Olympics, but it's up to the selectors whether they want to take me or not. I believe I can go to Rio and have a chance."
The home supporters had something to cheer about in the men's sprint where Olympic champion Jason Kenny was in magnificent form, winning the third world title of his career, but first in three years.
Three-time Olympic gold medallist Kenny has earned a reputation for failing to perform in non-Olympic events, but he eased into the final before defeating Australia's Matthew Glaetzer 2-1 in the best-of-three competition.
Kenny lost the first race but showed great tactical awareness and power to beat his rival in the last two rides.
"It was epic, I'm absolutely shattered," said Kenny. "I'm over the moon.
"That was definitely my hardest world title I've won. To win the sprint is special.
"Twelve months ago I remember sitting in the stands, watching the semi-final and the final and it just seemed like a world away. I'd been first-round fodder and we'd all gone home early.
"I don't think I'll ever feel like I'm ready for Rio. You always feel like you need to have more time. The key thing is now between now and the Games - doesn't matter whether we've won here or lost - it's about making the most of every day. To win in Rio we know we'll have to go better again."
Poland's Katarzyna Pawlowska won the women's points race in London, capturing the third world title of her career.
Twice a world champion at the scratch race event, Pawlowska took the lead at the seventh of the 10 sprints and never surrendered her advantage.