In 1967, he was invited to join the athletics team of Sporting Clube de Portugal, where his coach was Mário Moniz Pereira,[10] and remained there until the end of his career in 1985.

In the race, Lopes set the pace from the 4000 metres mark, and the only athlete to follow him was defending double Olympic champion Lasse Virén.

[13] In the following year, Lopes finished second to Leon Schots in World Cross Country Championships in Düsseldorf, Germany.

In 1982, Lopes returned to top form, and in Oslo, Norway, he broke the 10,000 metres European record with a time of 27:24.39, which belonged to his teammate Fernando Mamede.

At the 1982 European Athletics Championships in Athens, Greece, Lopes finished fourth in the 10,000 metres with a time of 27:47.95, behind the winner Alberto Cova.

An accident almost prevented Lopes from participating in the 1984 Summer Olympics in Los Angeles when, a week before the Games, he was run over by a car in Lisbon but he was not hurt.

This victory established his reputation as a world class runner, because he ran the last 7.2 kilometres (4.5 mi) at an average speed of 2:55 per km (4:42 per mile), a remarkably quick pace at the end of a marathon.