After a series of nail-biter qualification heats, all three Americans earned their spots into the semifinal round of the women's 800 meters on Thursday at the IAAF World Championships in London. 

American record-holder Ajee Wilson qualified for the semifinal with ease in 2:00.52 to win the first heat of the day. 

After some jostling out of the second heat, Brenda Martinez earned a fourth-place finish in 2:01.53. Ultimately, she qualified for the semifinal on time. Angelika Cichoka kicked to win with a 2:00.86 final time, followed by 2015 world silver medalist Melissa Bishop and Great Britain's Shelayna Oskan-Clarke. 

After finishing third in the 1500m final three days earlier, Caster Semenya recovered from her performance and won the third heat with a time of 2:01.33. 

Margaret Wambui looked extremely strong when she won heat four in 2:00.75 over Lynsey Sharp. The Kenyan athlete earned a bronze medal at the 2016 Olympic Games. 

Surprisingly, 2013 world champion Eunice Sum did not start heat five. The last time she raced was a 1:57 third-place finish at the Lausanne Diamond League meet in July. Charlene Lipsey earned the victory out of the heat with a winning time of 2:02.74. Lipsey is in the middle of a breakthrough year after shattering her personal best with a 1:57 at the Lausanne Diamond League meet. 

To end the first round, Olympic silver medalist Francine Niyonsaba won the sixth heat in 1:59, which was the fastest time of the day. 

The semifinal will takes place on Friday at 1:30 p.m. CT.

Full list of semifinal qualifiers:

POS	ATHLETE	COUNTRY	RESULTS
1	Francine NIYONSABA	BDI	1:59.86 Q
2	Habitam ALEMU	ETH	2:00.07 Q
3	Selina BÜCHEL	SUI	2:00.23 Q
4	Adelle TRACEY	GBR	2:00.28 q PB
5	Ajee WILSON	USA	2:00.52 Q
6	Margaret Nyairera WAMBUI	KEN	2:00.75 Q
7	Angelika CICHOCKA	POL	2:00.86 Q SB
8	Noélie YARIGO	BEN	2:00.99 Q SB
9	Lynsey SHARP	GBR	2:01.04 Q
10	Melissa BISHOP	CAN	2:01.11 Q
11	Christina HERING	GER	2:01.13 q
12	Egle BALCIÜNAITÉ	LTU	2:01.21 Q SB
13	Hanna HERMANSSON	SWE	2:01.25 q
14	Shelayna OSKAN-CLARKE	GBR	2:01.30 Q
15	Caster SEMENYA	RSA	2:01.33 Q
16	Rose Mary ALMANZA	CUB	2:01.43 Q
17	Sanne VERSTEGEN	NED	2:01.50 q
18	Joanna JÓZWIK	POL	2:01.51 Q
19	Brenda MARTINEZ	USA	2:01.53 q
20	Gena LÖFSTRAND	RSA	2:01.73 q