Alonso's every touch was jeered by the Toluca fans during Tuesday's match in the Mexican city. Its position, 2,600 metres above sea level, was the reason the Uruguayan gave for leaving last July.
Alonso, who played the full 90 minutes on Tuesday, scored in the 56th after two goals from fellow striker Vicente Sanchez in the previous 10 minutes had erased Toluca's lead in the Group One match.
Alonso, who top-scored with 25 goals in the 2011/12 season in the Mexican first division after joining Toluca from Espanyol, said last July he was retiring to comply with his family's wishes.
"I've decided not to carry on any more in football, whatever the medical diagnosis," the 33-year-old striker was quoted as saying at the time after a heart problem became apparent in a routine club medical check-up and playing at high altitude was deemed a risk.
"My family have asked me not to play any more. A team mate, Dani Jarque, died in my arms," he added.
Spanish former Espanyol defender Jarque died of a heart attack at the age of 26 at a preseason camp in Italy in August 2009.
Doctors in Mexico said Alonso, who spent 11 years in Spain with Alaves, Real Murcia and Espanyol, might be able to continue playing but he stuck to his plan to leave Toluca and return home to Montevideo.
Alonso changed his mind last month during the summer recess and joined Uruguayan champions Nacional, who have won the Libertadores Cup three times, getting a shot at playing in South America's elite club competition.
Toluca, struggling in the Mexican league, stunned six-times South American champions Boca Juniors 2-1 in Buenos Aires in their opening group match last week.
Nacional opened with a 2-2 draw at home to Ecuador's Barcelona thanks to Alonso's added-time equaliser.
- Sports & Recreation