In a free-flowing game Ecuador made the most of their opportunities and were deserved winners over a Polish team who worked hard across the park without reward.
Poland were not without chance as they hit the woodwork twice and often got themselves into good goal scoring position only to be thwarted at the crucial moment.
Down at the break, the Poles came out chasing the match in the second half with midfielder Jacek Krzynowek called for a dubious offside in the 52nd minute when he was put through to be one on one with Ecuadorian keeper Cristian Mora.
65th minute substitute Ivan Kaviedes repaid coach Luis Suarez’s faith when he sprung the offside trap 15 minutes after coming on and put Agustin Delgado clear to slot home into an open goal.
Ecuadorian captain and influential defender Ivan Hurtado was substituted in the 69th minute due to an injury to his right ankle, but his team were able to keep a clean sheet without him to help secure victory.
Earlier, both teams played out a tentative first 15 minutes to open their World Cup campaigns before Tenorio opened the scoring in the 24th minute.
Poland's Euzebiusz Smolarek fights
A long throw-in was flicked on by a leaping Delgado with Tenorio, who plays club football for Al Sadd in the Qatari league neatly finishing with a deft header past keeper Artur Boruc.
Both Delgado and Tenorio had been battling to be fit for their team’s opening match, but combined beautifully to open the game up with a first half goal.
Poland went on several attacking forays in the first stanza, but often their final ball let them down with Mora cleaning up at the back – a trend that continued throughout the match on a frustrating night for the Poles and coach Pawal Janas.
Ecuador take on Costa Rica in their next match on 15th June in Hamburg while Poland have a tough task ahead, travelling to Dortmund to face impressive first up winners Germany on 14th June.