Blenkinsop, 24, had to settle for a much merited fourth placing in the gravity finals, finishing 0.4s off the podium at the Cascades Mountain Bike Park in Pietermaritzberg.
The Wanganui competitor, who rides for Lapierre International, is the only Kiwi elite male mountain biker to podium at the world championships when he placed third in France in 2011.
“From the start I was aiming at the top five so the weekend went well for me,” Blenkinsop said. “I was strong and I had the physicals for this course. I just wish it had got me on to the podium – it’s so close.”
There were three New Zealanders in the top-20 with Trek World Racing rider George Brannigan (Havelock North) back to top form after injury to finish 13th and Taranaki’s Wyn Masters enjoying his best world championship finish in 17th. World No 10 ranked Brook MacDonald had to settle for 24th and Louis Hamilton (Rotorua) 52nd.
Blenkinsop’s brave effort to add a second world championship medal came up just short by the closest of margins on a course that is longer and less technical than the archetypal downhill run.
Australian Jared Graves, a former four-cross world champion, clocked 4:01.391 to grab the hot seat with six riders remaining. The New Zealander, next up, was fastest through the first split on the 3.01km course but finished in 4:01.804.
“You have to smash the pedal to do well on this course. You don’t want to over-smash it because you had to save some legs for the bottom but I wish now that maybe I could have hit it a bit harder at the top but at least I was really strong for the finish,” Blenkinsop said.
Another Australian Michael Hannah took the lead off Graves but he was edged out for the by hometown favourite Greg Minnaar, who won his third rainbow jersey.
Blenkinsop said improved fitness was a key, while he enjoyed the longer course.
“We’ve raced here from years before so I knew it was going to be a hard one with the physical. I have done some different training and I feel a lot fitter than before.
“I’ve been doing the enduro series races and I think I am stronger than in previous years. I guess all the gym work and this pays off.
“I tend to struggle on the shorter courses because I make mistakes. A long course like this I can build my speed and get faster as the run goes on.”
England’s Rachel Atherton continued her stellar season to claim the women’s title from two-time world champion Emmeline Ragot (FRA) who trained in New Zealand over the summer.
Earlier Australian Paul van der Ploeg won the country-country eliminator final with the three kiwis, Anton Cooper, Sam Shaw and Sam Gaze missing out on qualification for the elimination rounds. Teenager Gaze (Te Awamutu) was 20th, just four spots off the cut.
Results, elite men: Greg Minnaar (RSA) 3:58.058, 1; Michael Hannah (AUS) 3:58.454, 2; Jared Graves (AUS) 4:01.391, 3; Sam Blenkinsop (NZL) 4:01.804, 4; Matthew Simmonds (GBR) 4:01.997, 5. Also New Zealanders: George Brannigan 4:05.985, 13; Wyn Masters 4:09.375, 17; Brook MacDonald 4:12.871, 24; Louis Hamilton 4:22.002, 52.
Elite women: Rachel Atherton (GBR) 4:28.043, 1; Emmeline Ragot (FRA) 4:36.675, 2; Tracey Hannah (AUS) 4:40.438, 3; Jill Kintner (USA) 4:41.468, 4; Caroline Buchanan (AUS) 4:41.655, 5.
Cross-country eliminator, men final: Paul van der Ploeg (AUS) 1; Daniel Pederspiel (AUT) 2, Catriel Soto (ARG) 3.
Women final: Alexandra Engen (SWE) 1; Jolanda Neff (SUI) 2; Linda Indergand (SUI) 3.