Sanya Richards of the United States wins her 400m semi-final in Berlin (© Getty Images)
Some have accused this eventSanya Richards apart - of being a little low-key, a little under par this season. No more. The three semi-finals served up personal bests, national records and a glut of sub-50 second times which makes any predictions for the outcome of Tuesday's final a dangerously precarious business.
Right, first things first. For the second successive round the World and Olympic champion Christine Ohuruogu was pitched into the same heat as World No.1 Sanya Richards. Many before the competition viewed this pair as the most likely gold medallists, and both advanced comfortably from the third semi-final. Richards, of the USA, looked good, kicking into the lead around the final bend and coasting down the home straight to stop the clock in 50.21. Ohuruogu entered the home stretch in third, before her trademark strength took hold. She powered past Russia's Lyudmila Litvinova and closed down rapidly - albeit on an easing down Richards - to record a season's best 50.35 for second. Both qualified for the final and were suitable impressive.
Yet it was the first two semi-finals that produced the real fireworks and a measure of their quality can be summed up by the fact that although Richards and Ohuruogu secured the two automatic qualification places, they were only the sixth and eighth fastest qualifiers for the final.
The scene was set in a high-class semi-final in which World bronze medallist Novlene Williams-Mills of Jamaica shaded Botswana's Amantle Montsho by 0.01 in a season's best of 49.88. Montsho, too, produced her fastest run of the year - and came within 0.06 of her lifetime best - to secure the second automatic qualification spot. Russia's Anastaysiya Kapachinskaya finished third in 50.30 and squeezed through as one of the two fastest losers. In fourth Aliann Pompey of Guyana was rewarded for an agressive run with a national record of 50.71.
Yet if that was impressive, the quality lifted another notch in the second heat in which Jamaica's Olympic silver medallist Shericka Williams produced the fastest ever women's 400m semi-final in World Championship history to shatter her personal best in 49.50.
Williams (no relation to Williams-Mills) produced a conservative first half of the race before streaking clear of the field down the home straight to hack 0.19 from her previous best.
In a high-class heat, the long-time leader World No.2 Antonia Krivoshapka of Russia recorded 49.67 - the second fastest qualification mark of the round - while Debbie Dunn also shattered her personal best by a massive 0.71 to record 49.95 for third. The 31-year-old American advanced to the final as one of the two fastet losers.
Such was the quality of all three semi-finals that the 2007 World silver medallist Nicola Sanders just missed out on a place in the final, despite recording a more than respectable season's best of 50.45 for fourth in the second semi-final. Roll on Tuesday night.
Steve Landells for the IAAF
