Eliseu's clinical strike in Tuesday's 1-1 draw at seven-times winners AC Milan, his third goal of the competition, was the latest step in a remarkable journey that began in Spain's second division.
After joining from Portugal's Belenenses, Eliseu helped Malaga win promotion back to the Spanish top flight and an injection of Qatari cash in 2010 has seen them reach heights he could never have imagined.
He might even have missed the party as media reported he was seeking a move to Benfica in the pre-season amid speculation Malaga owner Sheikh Abdullah Bin Nassar Al Thani wanted to sell up and cashflow problems caused delays in wage payments.
After a summer of uncertainty, Al Thani has indicated he plans to continue investing in the club and in the Champions League knockout round the players now have the perfect platform to prove to him it will be worth the effort.
"It feels as if it were only yesterday that we were down in the second division fighting to the death," Eliseu, who can play as a full-back or midfielder and has a fearsome left-foot shot, said in an interview with Spanish TV after the Milan game.
"Now we are here sealing qualification in the San Siro, it's a dream," added the 29-year-old, who was born on the remote mid-Atlantic Azores islands.
"Now we have to hold on to our place and make sure of top spot in the group and we'll continue to fight for that."
With four of six matches played, Malaga have 10 points, with Milan on five, Anderlecht on four and Zenit St Petersburg on three.
Victory at Zenit on November 21 will ensure first place and make it more likely Malaga will avoid the big guns in the next round.
Eliseu, whose goal five minutes before halftime was cancelled out by Alexandre Pato's second-half header, said he and his team mates had been concentrating on their football rather than worrying too much about the club's problems.
"We are on the margins of everything and focused on the pitch and there we are doing the business," he said. "We have to carry on in the same way, above all to send a message to the owners of the club."