Bolton's European adventure continued after a 0-0 draw saw them beat Atletico Madrid 1-0 on aggregate to reach the last 16 of the UEFA Cup.
Holding a slender 1-0 lead from last week's third-round first leg, Wanderers produced a perfect defensive performance in the Spanish capital.
That result was enough to send Gary Megson's side through to a meeting against Sporting Lisbon in the next round.
Atletico had never previously lost at home to an English club in European competition.
The Spaniards had also won their last seven European ties at the Vicente Calderon, scoring 16 goals and conceding just one.
However their poor recent form, which has seen them lose five of their last eight competitive matches, gave Bolton hope, and the Trotters added to those woes with a battling display that left Atletico empty-handed and out of Europe.