Manu Vunipola’s nerveless late penalty handed reigning champions Saracens a dramatic 16-13 win over valiant newly-promoted London Irish at Allianz Park on Saturday.

Saracens tied the game at 13-13 with just two minutes left when young back row Ben Earl dotted down off the back of a driving maul and although Vunipola missed the conversion, he made amends with a successful penalty with the final kick of the game.

On the day that the 19-year-old's cousins Billy and Mako suffered World Cup final heartbreak with England, the Vunipola family had something to celebrate at least and director of rugby McCall was impressed by the teenager's ability to hold his nerve under pressure.

"We gave ourselves that one opportunity we needed," he said. "It was a great moment for Manu as a young player.

"He has a very good temperament, and to step up to kick the winning penalty shows quite a lot of it. Having missed the one before, it increases the pressure, but he did well.

"We're relieved but we experienced the opposite emotion a couple of weeks ago when the opposition (Northampton) kicked a penalty in the last second. We should enjoy what happened in the last five minutes."

Saracens have two wins from three Premiership games and with their World Cup stars soon to return, McCall is positive.

"This was always going to be a testing period for us with so many players at the World Cup," he added.

"This group have shown some real grit and been prepared for tough games. To have nine points from three games is pretty decent.

"We need to let the dust settle after the World Cup final, give them some space, talk to the players individually and see how they feel before we make any decisions."