The women's 400 metres competition at the 2012 Summer Olympics took place from 3 to 5 August at the Olympic Stadium, in London.

London rains became a part of the qualifying round, where the favorites tried to make the final with minimum effort. 52.11 was the slowest qualifying time, though Tjipekapora Herunga managed a 52.31 for the slowest automatic qualifier.

In the semi-final, the weather was better. In the first semi, Sanya Richards-Ross was matched with the defending champion Christine Ohuruogu, with only two automatic qualifiers. At the gun, Richards-Ross took off, making up most of the stagger on Krivoshapka to her immediate outside. Relaxing the backstretch but exploding on the second turn, Richards-Ross had built up a huge lead, then slowed considerably on the home stretch letting Ohuruogu gain almost all the lead back. The second semi turned into a match race between Francena McCorory and world champion Amantle Montsho, running stride for stride together far ahead of the others until Montsho dipped to place first. The third semi was a much faster affair. 2012 World leader Antonina Krivoshapka took the race out as if it were the final, making up the stagger during the first turn and coming off the turn with a huge lead. She also slowed on the homestretch and looked to struggle to hold off DeeDee Trotter and Novlene Williams-Mills. Third place Williams-Mills became a time qualifier faster than the previous two heats.

In the final, unlike the memorable race four years earlier, where Richards-Ross burned herself out building a huge lead, this time Krivoshapka had the large lead through the halfway mark and held it to the home stretch, with the three Americans spread across the track a step behind. McCorory and Krivoshapka began to struggle as first Trotter, then Richards-Ross seized the lead which she would not relinquish, winning by 0.15 seconds. Before the home crowd, Ohuruogu approached the finish line with a trademark late surge, coming from several steps off the pace to catch Deedee Trotter for the silver medal, Trotter holding on for the bronze.

Competition format The women's 400m competition consisted of heats (Round 1), Semifinals and a Final.

Records , the existing World and Olympic records were as follows.

World record47.60Canberra, Australia6 October 1985Olympic record48.25Atlanta, United States29 July 19962012 World leading49.16Cheboksary, Russia5 July 2012

Schedule

All times are British Summer Time (UTC+1) Date Time RoundFriday, 3 August 2012 12:00Round 1Saturday, 4 August 2012 20:05SemifinalsSunday, 5 August 2012 21:10Finals

Heats

Entrants as of 27 July 2012.Entry List by Event. IAAF (2012-07-27). Retrieved on 2012-07-29.

Qual. rule: first 3 of each heat (Q) plus the 3 fastest times (q) qualified.

Heat 1

Rank Athlete Nation Time Notes 1 Francena McCorory 50.78 Q 2 Christine Ohuruogu 50.80 Q 3 Joy Nakhumicha Sakari 51.85 Q, SB 4 Joanne Cuddihy 52.09 q 5 Geisa Aparecida Coutinho 53.43 6 Marina Maslenko 53.66 7 Zamzam Mohamed Farah 1:20.48

Heat 2 Rank Athlete Nation Time Notes 1 Amantle Montsho 50.40 Q 2 Christine Day 51.05 Q 3 Shana Cox 52.01 Q 4 Aliann Pompey 52.10 q, =SB 5 Afia Charles 54.25 6 Ingrid Yahoska Narvaez 59.55 =SB Shaunae Miller

Heat 3

Rank Athlete Nation Time Notes 1 DeeDee Trotter 50.87 Q 2 Rosemarie Whyte 50.90 Q 3 Jenna Martin 51.98 Q 4 Omolara Omotosho 52.11 q 5 Raysa Sánchez 52.47 6 Aauri Bokesa 53.67 7 Zourah Ali 1:05.37

Heat 4

Rank Athlete Nation Time Notes 1 Sanya Richards-Ross 51.78 Q 2 Carol Rodríguez 52.19 Q 3 Tjipekapora Herunga 52.31 Q 4 Pınar Saka 52.38 5 Sviatlana Usovich 52.40 6 Phumlile Ndzinisa 53.95 7 Hristina Risteska 1:00.86

Heat 5

Rank Athlete Nation Time Notes DSQ Antonina Krivoshapka 50.75 Q 2 Alina Lohvynenko 52.08 Q 3 Lee McConnell 52.23 Q 4 Moa Hjelmer 52.86 5 Ambwene Simukonda 54.20 NR 6 Danielle Alakija 56.77 Kanika Beckles

Heat 6

Rank Athlete Nation Time Notes 1 Novlene Williams-Mills 50.88 Q 2 Nataliya Pyhyda 51.09 Q, PB 3 Libania Grenot 52.13 Q 4 Joelma Sousa 52.69 5 Bianca Răzor 52.83 6 Maziah Mahusin 59.28 NR Kineke Alexander

Heat 7

Rank Athlete Nation Time Notes 1 Regina George 51.24 Q 2 Yuliya Gushchina 51.54 Q 3 Marlena Wesh 51.98 Q 4 Amy Mbacké Thiam 53.23 5 Olesea Cojuhari 53.64 6 Graciela Martins 58.30 Jennifer Padilla Jennifer Padilla originally finished in third place with a time of 51.74, but was disqualified due to lane infringement. As a result, Marlena Wesh moved up to third position to qualify for the semi-finals.

Semi-finals

Qual. rule: first 2 of each heat (Q) plus the 2 fastest times (q) qualified.

Heat 1

Rank Athlete Nation Time Notes 1 Sanya Richards-Ross 50.07 Q 2 Christine Ohuruogu 50.22 Q, SB 3 Rosemarie Whyte 50.98 q 4 Yuliya Gushchina 51.66 5 Joanne Cuddihy 51.88 6 Tjipekapora Herunga 52.53 7 Jenna Martin 52.83 8 Joy Nakhumicha Sakari 52.95

Heat 2

Rank Athlete Nation Time Notes 1 Amantle Montsho 50.15 Q 2 Francena McCorory 50.19 Q 3 Libania Grenot 51.18 4 Christine Day 51.19 5 Regina George 51.35 6 Alina Lohvynenko 51.38 7 Aliann Pompey 52.58 8 Shana Cox 52.58

Heat 3

Rank Athlete Nation Time Notes DSQ Antonina Krivoshapka 49.81 Q 2 DeeDee Trotter 49.87 Q, SB 3 Novlene Williams-Mills 49.91 q 4 Omolara Omotosho 51.41 5 Nataliya Pyhyda 51.41 6 Carol Rodríguez 52.08 7 Lee McConnell 52.24 8 Marlena Wesh 52.49

Final Rank Lanes Athlete Nation Time Notes 6 Sanya Richards-Ross 49.55 8 Christine Ohuruogu 49.70 SB 4 DeeDee Trotter 49.72 SB 4 7 Amantle Montsho 49.75 5 2 Novlene Williams-Mills 50.11 6 9 Francena McCorory 50.33 7 3 Rosemarie Whyte 50.79 N/A 5 Antonina Krivoshapka 50.17 DSQ

References