Andy Murray won his first ATP Tour level match in Europe for 16 months as he continued his encouraging return from hip surgery.
The former world number one, making his first appearance at the European Open in Antwerp, beat Belgian wild card Kimmer Coppejans 6-4 7-6 (4).
Murray was given a decent work-out by the world number 158, who has yet to win a match on the Tour.
The Scot's serve remains rusty and, after racing into a 3-0 lead, he was broken back courtesy of three double faults.
It proved a minor blip, Murray breaking in the 10th game to take the first set in 40 minutes.
Yet two more breaks of the Murray serve meant he was dragged the distance in the second.
But he got over the line after a tie-break, wrapping up victory in an hour and 44 minutes to reach the last 16.
It was the two-time Wimbledon champion's first victory on European soil since beating Stan Wawrinka at Eastbourne in June 2018.
Antwerp is likely to be Murray's last tournament of the year, with the possible exception of the Davis Cup next month.
He will face eighth seed Pablo Cuevas of Uruguay or Bolivian Hugo Dellien in the last 16.
Veteran Spaniard Lopez claimed the only break of serve in the fifth game of the second set and went on to record a 7-6 (2) 6-4 victory after an hour and 29 minutes.
Norrie, ranked 61, had Lopez at 0-40 in the final game of the match but was unable to break back.
Despite the defeat, Norrie will become the British number two on Monday behind Dan Evans, with defending champion Kyle Edmund set to drop outside the top 70 after falling in qualifying.