France, March 17 -- The sides play on Tuesday night at Stamford Bridge in west London for a place in the quarter-final against Liverpool or Galatasaray.

Enrique, who guided PSG to the Champions League crown last May, said on the eve of the clash that the first leg at the Parc des Princes underlined the sport's fine margins.

"Seventy minutes into the last game, it was 2-2," he recalled. "And in the final minutes, we managed to come out on top. But before that, it was tight and difficult.

"For the second leg we can't afford to let our guard down," he added. "What we're aiming for is to control the game, even if it's impossible to do so completely."

Khvicha Kvaratskhelia emerged as the star of the first leg on 11 March.

The 25-year...