Internationals fighting back

All 12 of Sunday's Presidents Cup single matches are underway at Royal Melbourne and the Internationals are making a half-decent fist of achieving the nine wins they need to claim the Cup.

By the time the final pairing of Steve Stricker and Y.E. Yang teed off at 12.42pm (AEDT), the Internationals were leading in five matches, the U.S. led four and two matches were all-square.

The big talking point on course has been the performance of an out-of-sorts Phil Mickelson.

The Americans' most experienced player, who was rested from Saturday afternoon's four-ball to prepare for his singles clash with Adam Scott, conceded the opening three holes to his International opponent.

The 42-year-old has been playing catch-up from the moment he carved his opening tee shot into the tee tree that lines the first fairway.

Annoyed and frustrated, at one point Mickelson's wife Amy had to chase after him to try to calm him down.

It didn't do much good - he slipped to four-down with a bogey at the par-three fifth.

International team captain Greg Norman demanded a strong start from his early players and, so far, that's the way it's gone.

In the opening match, K.T. Kim was two-up at the turn against Webb Simpson, following immediately behind Charl Schwartzel was three-up through nine against Dustin Johnson and Ryo Ishikawa led Bubba Watson by two holes after eight.

The Americans have had the better of the later matches, however.

Hunter Mahan led Jason Day by three holes through six, Nick Watney was two-up against K.J. Choi also through six and Jim Furyk had a one-hole break on Ernie Els after three completed holes.

Day, who came into this event as the Internationals' leading hope, has had a shocker, spraying the ball all over the place.

The 24-year-old doesn't look likely to add to the one and-a-half points he's secured from four matches over the previous three days.

Trailing the Americans 13 points to nine after the completion of Saturday's foursomes and four-ball matches, the Internationals are attempting to claim the Presidents Cup for just the second time.

Conditions at Royal Melbourne are bright and breezy.

There's a chance of afternoon showers with temperatures forecast in the low-20s.