Sporting rivalries occasionally move beyond the realms of hype into the domain of the sublime and surreal. This was the territory explored in the penultimate episode of the Victoria Pendleton versus Anna Meares saga, which ended with the Briton taking her sixth world title, regaining the crown she surrendered to the Australian in Holland last year. For once the pre-race polemic was upstaged by the main event, although among the war of words came this prescient comment from Meares: "All sportspeople push the limits. Sometimes the lines get crossed and the people who make the judgment on that are the commissaires."

As a summary of the extraordinary tale of one evening's event it is hard to better. Limits were pushed by the Briton, the Australian and the eventual defeated finalist, Simona Krupeckaite of Lithuania. Lines were crossed – rarely has the red sprinters' lane played such a key role – and the commissaires tried to make sense of it all. Pendleton and Meares have three dates this year: in February in London they turned each other inside out in a three-round epic; round two here left honours even; and there is the prospect of a grand finale at the "Pringle" in London in August.

At the start of the evening session few would have given Pendleton a chance of regaining the title. She had been way behind the record-breaking Australian in qualifying, looked sluggish in her first two rounds but appeared sharper in the quarter-final. History was against her as well: since taking the world title in 2010 Meares had taken their every encounter, usually in a semi-final. In desperation the coaches opted to increase Pendleton's gear massively, hoping she could run Meares long and hard and wear her out. As she sat by the track beforehand, she had the look of a woman waiting for the gallows, lip atremble.

The first match appeared to be going the way of Meares, who was overhauling Pendleton in the finish straight as the Briton veered to her right, losing control as she briefly hit the Australian. Down she went on her right shoulder. "She hit hard, I saw it, I heard it, I felt it," said Meares, who added that the move would have had Pendleton relegated. As Pendleton sprawled, her rival gave an ironic little salute.

Once the Briton had been dusted off and her trackrash seen to, it was on to round two. Again Meares looked in control but as she held off Pendleton on the final banking, she jinked her back wheel upwards, going above the red line that decides whether a sprint is straight or not. Pendleton had to switch upwards to avoid her front wheel colliding with Meares's rear wheel, and as sure as night followed day, the relegation came. That made it one-all, Meares having thrown away a victory that looked assured. It will haunt her until August at least. Round three was where Pendleton showed the quality that would win her the day: sheer bloody-minded grit. Meares had been rattled and showed it with a little kick of the back wheel as she dived at the bell; the Australian attacked but left just enough of a gap for Pendleton to use her slipstream to inch her way past in the finish straight. "Anna panicked and went for home" was the summary of the GB head coach, Shane Sutton.

In the final Pendleton was up against Krupeckaite, a seasoned campaigner with two world titles but none of the psychological baggage Meares brings with her. She is no bogeywoman and match one went Pendleton's way. Then came the final twist: a seemingly straightforward victory for Krupeckaite in match two, in which, having swung all the way up the track on the penultimate banking, she was disqualified for veering outside the red on the back straight. Pendleton was warming up for the decider when she was told: the news took 10 seconds to register. Cue a sea of tears and hugs in the British pits.

Her reward was massive: a sixth match sprint title putting her level with the record holder for the event, the Russian Galina Tsareva, an amateur of the Brezhnev era. Critically Pendleton goes on to London with what, for this most tortured of riders, might be dangerously close to peace of mind. "It's the most significant of my titles," she said. "It's the last time I will do this, it means as much as my first [title] when I didn't think I had the ability. It feels weird and iffy to win when you don't cross the line first but those are the rules. It gives me a lot of confidence."

The duel between track cycling's two divas overshadowed the day's other events, headlined by some superb action from the men's sprinters, 10 of whom qualified in under 10sec for the flying 200m. Both Sir Chris Hoy and Jason Kenny ended up winning through to the semi-final the hard way, over three rounds against the German Robert Förstemann and France's Kévin Sireau. The two Britons will meet in a semi-final that could go a long way to deciding which of them fills the single sprint slot available for London.

While Ed Clancy followed up his superb team pursuit gold with an agonising near-miss – fourth, level on points, decided through countback – in the men's omnium and Laura Trott stands a good chance of a medal on Saturday in the women's race after winning the elimination race, that was mere Mills and Boon compared with the blockbuster jointly penned by Pendleton and Meares. The latter summed up: "It is a book that hasn't finished being written." Roll on the final chapter. Whatever its conclusion, one thing is certain: Pendleton will leave cycling as a world champion.