Atletico Madrid's bid to reach a third Champions League final in four years got off to a winning start with a hard-fought 1-0 victory over PSV Eindhoven.
Saul Niguez's acrobatic strike just before half-time settled an eventful encounter at the Philips Stadion as Atletico claimed a valuable away win in what is a tough-looking Group D.
PSV had the chance to net an immediate equaliser after winning a hugely controversial 45th-minute penalty, but Andres Guardado saw his spot kick superbly saved by Jan Oblak
Atletico, runners-up to arch-rivals Real in the 2014 and 2016 finals, had beaten PSV in last season's Round of 16 following a battle that had to be settled by penalties after both legs finished goalless.
PSV had vowed to avenge that disappointment on Tuesday night and they thought they had been handed a flying start when captain Luuk de Jong headed home in the fifth minute.
However, the home side's jubilant celebrations were cut short by referee Martin Atkinson, who had seen a foul in the build-up.
If PSV were upset by that decision, their mood would not have improved when Atletico took the lead in the 43rd minute.
Gabi's right-wing corner made its way through to Saul near the penalty spot and, although his first effort was blocked, the rebound came back to him and he thumped a superb volley into the corner of the net.
The home side protested to the officials, seemingly upset play was allowed to continue while their defender Davy Propper was prone in the six-yard box with blood gushing from a clash of heads with Atletico's Jose Gimenez.
The goal stood but the officials were the centre of attention again moments later as PSV won a hugely debatable penalty, Luciano Narsingh going down following a challenge by Gimenez despite there appearing to be no contact.
Gimenez was left stunned as Atkinson pointed to the spot, the Uruguayan centre-back in the process of demanding Narsingh be booked for diving, but Atletico will feel justice was done as Oblak flung himself to his left to turn away Guardado's well-struck penalty.
Atletico missed several chances to build on their lead in the second half but PSV were unable to make any headway at the other end, with substitute Gaston Pereiro missing a great chance late on when he headed straight at Oblak in stoppage time.