Rory McIlroy enjoyed making his pitch as US Open champion – now the real work is set to begin.

The 23-year-old Irishman was the guest of honor when the San Francisco Giants played on Tuesday night.

As the current champ, McIlroy threw the ceremonial first pitch when the Giants hosted the Houston Astros.

Having practised with a golf ball for weeks – he sought out the advice of Graeme McDowell during a US Open practise round on Monday – Wee Mac was happy with his efforts.

And the 35,000 fans agreed as they cheered as he lobbed a neat throw to the hands of the catcher and held his arms aloft to soak up the acclaim.

He said: “I’m so pleased I didn’t embarrass myself. You dread the thought of bouncing the ball miles short, or throwing it high over the catcher’s head. I was pretty pleased, I didn’t get any boos.”

McIlroy also approved of the 5,000 commemorative bobbleheads available at the game.

“I think they’re better looking than me,” he laughed ahead of Thursday’s first round at the Olympic Club in San Francisco.

Currently number two in the world, McIlroy will play alongside number one Luke Donald and number three Lee Westwood for the first two rounds of the US Open.

“It is going to be tough but I am looking forward to it,” he said.

AUGUSTA, GA - APRIL 03: Rory McIlroy of Northern IrelandAndrew Redington/Getty Images