|World Athletics Championships|
|Venue: Beijing National Stadium, China Dates: 22-30 August|
|Coverage: Live on BBC TV, Red Button, Radio 5 live, online, mobiles, tablets and app. Click here for full details.|
The Usain Bolt v Justin Gatlin re-match is on after both men dominated their semi-finals to charge into Thursday's 200m final.
Bolt, looking to retain his other individual sprint title after that extraordinary 100m victory here in the Bird's Nest, looked to be saving his strength for the next showdown as he eased off in 19.95 seconds.
Gatlin, comfortably the fastest man in the world this year over 200m, as he was over 100m, ran a controlled 19.87 as he seeks revenge for his shock defeat on Sunday night.
Britain's talented youngster Zharnel Hughes, who trains with Bolt in Jamaica, remains a shot for the podium as he won the first of the three semi-finals in 20.14.
|Selected fastest 200m times of 2015|
|19.57 seconds||Justin Gatlin (US)|
|19.80 secs||Rasheed Dwyer (Jam)|
|19.88 secs||Andre De Grasse (Can|
|19.95 secs||Usain Bolt (Jam)|
Gatlin, twice banned for doping, has run more than two tenths of a second faster than any other man in the field this year, and almost half a second quicker than Bolt.
The Jamaican holds the world record at 19.19 but has neither the times this summer nor the races, a pelvic injury restricting his season, and he was solid rather than spectacular round the bend.
But transitioning into the straight he was able to open a two-metre lead, and could coast the final 20m to save as much as possible for the battle ahead.
"I'm a bit tired as expected but just trying to get through these rounds," Bolt told BBC Sport.
"Right now I'm feeling OK. I didn't run a hard corner but I'm trying to preserve as much as possible for the final. The 200m is my best event."
Gatlin is desperate to take something away from the championships, having arrived as clear favourite to win back the 100m and 200m world titles he first won in Helsinki a decade ago.
|Lane draw for Thursday's 200m final|
|2. Femi Ogunode (Qat)|
|3. Ramil Guliyev (Tur)|
|4. Justin Gatlin (USA)|
|5. Zharnel Hughes (GB)|
|6. Usain Bolt (Jam)|
|7. Anaso Jobodwana (SA)|
|8. Nickel Ashemeade (Jam)|
|9. Alonso Edward (Pan)|
And the controversial 33-year-old got out well to dominate the second semi-final and stay on track for another head-to-head with his Jamaican nemesis.
"I didn't know I was running that fast," Gatlin said. "Hopefully I'll put more energy into the finals and come out on top."
I'm ready to take on the Best - Hughes
Hughes, born in the British Dependent Territory of Anguilla, formally gained British citizenship in June this year and won the national trials in some style.
In his first major global championship he is one of several athletes scrapping behind the big two, his win in his heat guaranteeing him a favourable lane draw for the final.
|Former British sprinter Darren Campbell on BBC Radio 5 live|
|"Zharnel Hughes could go on to break the British record one day and could get a bronze medal here. That was a fantastic, professional run. He didn't ease down too early. He wanted one of the middle lanes and to be taken seriously as a contender."|
Hughes told BBC Sport: "I hit my toe on the block and it kind of slowed me down when I got out.
"I wanted a great lane for the final and that's what I got. I train with the greatest in the world and I'm ready for them."
His compatriot Danny Talbot went out after finishing sixth from the lane outside Bolt but with a new personal best of 20.27.
Asher-Smith fastest in 200m heats
Britain's 100m champion and national record holder Dina Asher-Smith ran a superb personal best of her own of 22.22 to move into the semi-finals of the women's 200m.
The 19-year-old made light of her inside lane to run a splendid bend and then held her form down the straight to go close to Kathy Cook's 31-year-old British record.
"I'm really, really happy," Asher-Smith told BBC Sport. "I didn't expect to run a PB in the heat.
"I did feel relaxed which is why I was quite surprised with the time."
That time made Asher-Smith the fastest qualifier by more than two tenths of a second, 100m silver medallist Dafne Schippers [Netherlands] also impressive as she won her heat in commanding fashion, easing off in 22.58.
|Former world 400m champion Michael Johnson on BBC Sport|
|"Asher-Smith looks like she's been doing this for 10 years, but she's only 19. Let's see what she does over the next few years."|
Asher-Smith will be joined in Thursday's semi-finals by her team-mates Margaret Adeoye and Bianca Williams, but former world champion Veronica Campbell-Brown is fortunate to progress with them after running out of her lane off the band.
The hugely experienced Jamaican began in lane five but ran the final 90m in the sixth, coming home directly ahead of Adeoye.
But because she gained no advantage from going wider and did not impede the Briton, she could not be disqualified and, like Asher-Smith, is one of several athletes in medal contention in a very open event.