Atletico Madrid recorded a 1-0 win over Leicester City in the first leg.
English football champions Leicester City trained on Monday for the second leg of the Champions League quarter-finals against Atletico Madrid at the King Power stadium, as central defender Wes Morgan as well as Yohan Benalouane attended the training session after recovering from injuries.
It was Griezmann who inevitably received possession and scurried into Leicester's half and was awarded a controversial penalty.
The French worldwide put his previous penalty demons behind him to convert from the spot and put Atletico in the driving seat for a third semi-final in four seasons.
We're talking about a Champions League quarter-final.
He told BT Sport, as quoted by the BBC: "I think 1-0, we would have taken that before the game. It's a definite foul, but it's outside the box".
Atletico coach Diego Simeone recognised the difficulties of playing at the King Power and said he expects a raucous atmosphere in Leicester.
"But we are still alive and we want to stay in the competition".
"We know we have to be more open because we need a goal and one of Atletico's pluses is their ability on the counterattack", Shakespeare said.
Simeone's Atletico is trying to reach the semifinals for the third time in four seasons, while Leicester - the shock Premier League victor last season - is looking to make another stunning title run in its debut in the Champions League.
However, the 3,000 travelling supporters high in the rafters of the Calderon were largely silenced by Atletico's dominance of the match.
Yannick Carrasco then slashed wildly at a volley when well-placed at the back post.
Leicester failed to register a single shot on goal.
Leicester had been enjoying their best spell of the half when suddenly they were caught short-handed at the back on 27 minutes.
Griezmann sent Leicester keeper Kasper Schmeichel the wrong way from the spot after 28 minutes for his 24th goal of the season, while Fernando Torres missed a good chance to double the hosts' lead after the break.
"We know it will be a very hard return leg", he told a news conference.
The Leicester manager believes that his side can still turn things around in next week's second leg on their home turf, however.