Manu Vunipola demonstrated his impeccable temperament to steer Saracens to victory, according to director of rugby Mark McCall, as his side edged London Irish 16-13 at Allianz Park.

Saracens tied the game at 13-13 with just two minutes left when 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 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 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 Rugby 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."

Irish were unfortunate to only leave with a losing bonus point as Albert Tuisue's second-half try put them in front and they grimly held on until the late drama.

"Any time we lose a game like that, you're always going to be extremely disappointed at the end of it," said Exiles director of rugby Declan Kidney.

"Saracens are a club that are used to winning, and it takes a while to get that.

"What we're trying to do is be is the best team we can every time we take the pitch. There was a list of lessons we learnt from the Sale match (a 41-7 defeat last week).

"Every team brings a different type of challenge, so it's very hard to compare one with the other. I think we will learn lessons from this game and we will be better again in the next match."