LONDON — Next for Wayde van Niekerk comes the “easy” part: Trying to win the 200 meters.

After that, something more challenging: Becoming the face of track and field now that Usain Bolt is moving on.

It’s a daunting proposition. But Van Niekerk started off on the right foot by winning the 400 at the world championships. On Thursday, the South African standout goes for gold in the 200 – Bolt’s signature race. Only, Bolt is sitting this one out, ending his string of four straight titles in the event.

Pressure filling Bolt’s role? Van Niekerk insisted that’s not his mission.

Wayde Van Niekerk

“I’ve got a massive responsibility to continue performing, continue growing and continue winning medals,” said Van Niekerk, who qualified on time after finishing third in his semifinal heat on a rainy Wednesday. “That’s what’s important right now – continue the great legacy that the greats … have left behind. To continue to promote track and field.”

Van Niekerk certainly has impressive credentials. His top time – and personal best – in the 100 this year (9.94) would have tied for second at worlds had he run in London, and his 200 is good enough to win big events. He’s already the world-record holder in the 400.

That he’s even trying the 200-400 double is impressive. Bolt eventually chose the 100 over the 400 as his second race because the 400 is just that demanding. No arguments from Van Niekerk.

“Obviously, I know the pain that comes with (the 400) once I cross the finish line,” Van Niekerk said. “Very excited for the 200 – my body just needs to be ready and I’ll give it my best.”

Now that he’s almost retired, Bolt’s future endeavors will involve plenty of travel and very little training.

“I’m excited to just live normally,” said Bolt, the world-record holder in the 100 and 200.

In other action on Wednesday:

In the women’s 400, it was Phyllis Francis of the United States who upset the favorites.

Olympic champion Shaunae Miller-Uibo looked poised to win gold until she slowed in the final meters, seemingly with pain in her right leg.

Salwa Eid Naser swept past Allyson Felix near the line and lunged for silver, ahead of the American veteran.

Francis finished in 49.92 seconds, .14 seconds ahead of Naser. Felix took third in 50.08 and Miller-Uibo was fourth.

Despite her disappointing third-place finish, Felix won her 14th career medal at the world championships. That put her in a tie with Bolt and Merlene Ottey at the top of the list.

Bolt can still move to 15 with a medal in the 400 relay this weekend, but Felix might run on both relay races for the U.S. team, which could bring her to 16.

The biggest surprise on a cold and wet night came in the 400 hurdles. Karsten Warholm of Norway held off Yasmani Copello of Turkey and Kerron Clement of the United States for gold.

The first gold medal of the night went to Gong Lijiao of China, who won the shot put title ahead of Anita Marton of Hungary and Olympic champion Michelle Carter of the United States.