Complex sentence: Highlights included scoring at both home and away wins against Real Madrid in the year 1999 (separate seasons, both by 3--1); these happened to be Atlético's only competitive victories in the Madrid derby in a span covering almost 20 years.
Split into simpler sentences: Highlights included scoring at both home and away wins against Real Madrid in the year 1999 (separate seasons, both by 3--1). These happened to be Atlético's only competitive victories in the Madrid derby in a span covering almost 20 years.