I remember following it on a ticker, but wasn't televised where I lived at the time. It came as quite shock.
It was a Time Trial starting somewhere in Bedoin, so unless we know precisely where, comparisons are going to be inaccurate. It was 21.6km, and the riders were not fatigued after 15 stages of Grand Tour racing, or having raced 150km to get there, so time comparisons are going to be invidious. I don't recall the prevailing wind direction at the time either.
Besides Mayo, Hamilton was a close 2nd, followed by Oscar Sevilla and Mercado, with Armstrong 2 mins behind in fifth. Obviously, this is "Clinic" territory, but a few weeks later at the Tour, four of these riders had sunk without trace, only Armstrong had improved. Very characteristic of the times, and very different to what we have now, where riders are far more consistent (and predictable).