What's the fastest final 400 of a track race 800 and up? (videos please)

In 1992 in the olympic 1500m fermin cacho closed in 50.4 albeit off a slow pace

These last laps are given in approximate terms since there often isn't complete agreement on splits and some of them are hand timed anyway:

In 1,500s, Alex Kipchirchir apparently went 49-mid/high for the last lap to win the 2006 World Cup (a couple of others may have been sub-51 in that race), Jose Luis "Speedy" Gonzalez and Steve Cram ran 50-low to go 1-2 in the 1987 European Cup, Fermin Cacho (gold) and Rashid el Basir (bronze) closed in 50-mid in the 1992 OG final, Nourredine Morceli went 50-mid in the 1993 Worlds, Cram ran 50-high in the 1986 Euro, and Jim Ryun finished off in 50-high in the US vs. W. Germany meet way back in 1967 (this split is highly unofficial, but there's no question the last 300 was smoking fast). I think Said Aouita also once ran sub-51 in a 3:34-ish 1,500 but can't remember when.

In longer distance races, Abraham Chebii closed in 50-high in a slow (8:33) 3,000 in the 2002 Grand Prix Final.

Miruts Yifter supposedly ran 50-point at the end of a slow-ish 10,000 once, but there doesn't seem to be any official word on this. The quickest last lap I can remember in a distance race with a world-class final time was Bernard Lagat's 51-high at the end of a 12:59 5,000.

Sweet Nell Fenwick wrote:

Miruts Yifter supposedly ran 50-point at the end of a slow-ish 10,000 once, but there doesn't seem to be any official word on this. The quickest last lap I can remember in a distance race with a world-class final time was Bernard Lagat's 51-high at the end of a 12:59 5,000.

As far as I know, Yifter never has finished a 10k in 50.x, not even close. I doubt even sub 53.

Video of Jim Ryun's run?

One of 'em. Aouita supposedly broke 50 in a similarly slow 1500. Cram was not at his best in 1987, btw.

http://youtu.be/Cj8EJxCTQso

its probably Rudisha