Golf round-up: Colin Montgomerie broke his long American drought in style when he won the Senior PGA Championship by four strokes in Michigan on Sunday.

Montgomerie, who never won on the PGA Tour despite a decorated career in Europe, fended off a mid-round charge from Tom Watson to clinch the second Major of the season on the over-50s Champions Tour.

The Scot carded 65 to finish at 13-under-par 271 and evergreen American Watson made four birdies in five holes from the turn to shoot 65 and claim second place.

“It’s been a long time,” Montgomerie told NBC TV. “I haven’t won a 72-hole event in America until today. It’s a very special moment for myself and my caddie. We’ve been trying, my god we’ve been trying.

“We’ve come close on a number of occasions. It’s great to come here as a senior and finally break that duck.”

Montgomerie, who turned 50 last year, has won 31 times on the European Tour, where he topped the order of merit a record eight times, including seven seasons in a row.

But his only previous victory in the United States was at the 1998 World Championship Match Play event, which at the time was unofficial.

Montgomerie teed off with a one-stroke lead on Sunday and effectively clinched the title with six birdies in eight holes, starting at the eighth.

Any lingering doubts about the outcome disappeared when his second shot into the par-four 18th sailed long and left of the green, only to strike the grandstand and ricochet back onto the putting surface.

Watson, 64, was the only player to make a serious run at Montgomerie, who paid tribute to the man who will captain the American Ryder Cup team against Europe in September.

“If his Ryder Cup team has his ambition we’re in big trouble this year,” Montgomerie quipped, before continuing to talk about how much the victory meant.

“It’s a very difficult task to come from abroad and win in America. If you beat the Americans in America at any sport you’ve done really well.

“I’m very proud of myself, coming from little old Scotland and (winning) on American soil.”

Adam Scott celebrated his first week as world number one in emphatic fashion by winning the Crowne Plaza Invitational in Texas on Sunday.

Last year’s Masters champion notched his 24th professional victory, including 11 on the PGA Tour, by beating American Jason Dufner on the third play-off hole at Colonial Country Club after starting the day two shots off the lead.

Scott made a clutch 15-foot putt at the second extra hole to stay alive then sank a seven-foot birdie at the next to become the fourth Australian to win at Colonial, joining Bruce Crampton, Bruce Devlin and Ian Baker-Finch.

“I certainly didn’t play perfect this week, making a few errors, but it’s the way you come back and get it done and I felt like I certainly played like one of the best players in the world out there on the back nine,” Scott told reporters after becoming the first player to complete the so-called Texas Slam, following victories at the Houston Open (2007), Byron Nelson Championship (2008) and Texas Open (2010).

“It’s a real honour for me to win here. I was determined because I really wanted to win them all here in Texas.”

The week was not all smooth sailing for Scott, who was four over after nine holes on Thursday and also double-bogeyed the ninth on Sunday to dig himself into another hole.

But he recovered with three quick birdies, including a 40-footer at the 14th that gave him the lead and prompted a punch of the air with an outstretched index finger, as if to offer a reminder that he is number one.

He and Dufner shot 66 to finish on nine-under-par 271, one shot ahead of American Nicholas Thompson and Swede Freddie Jacobson.

Dufner, the reigning PGA Championship winner, looked set to claim his fourth tour title when he stuffed a nine-iron into four feet at the second extra hole.

But the newly-married Scott, 33, calmly drained his birdie attempt to set the stage minutes later for his first victory of the year.

“A ball-striker like Jason is going to hit one in close sooner or later and he did on 17,” Scott said. “To make the putt was huge.”

The final round began with 36 players within four strokes of the lead, but in the end the cream came to the top as Scott, who needed to finish 13th or better to stay atop the world rankings, found an extra gear as all of his rivals except Dufner stalled.

“I’m trying not to put too much pressure on myself to have to win every week to stay number one,” said Scott.

Rory McIlroy's dramatic victory in the BMW PGA Championship has lifted him four places in the latest world rankings.

McIlroy moves up from 10th to sixth following his one-shot win over his good friend Shane Lowry at Wentworth, with the two-time Major winner only taking the outright lead for the first time on the 71st hole.

Sweden’s Henrik Stenson has climbed to second after finishing joint seventh behind McIlroy, but that was not enough to overtake number one Adam Scott after his win in Texas.

Lowry jumped a massive 68 places in the world rankings to 74th spot after finishing alone in second place at Wentworth.

His cheque for €527,770 moves him up to 15th spot on the Race to Dubai standings with earnings this year of €560,749, with McIlroy breaking the million euro mark for the season. His earnings of €1,295,825 put him in second place behind Thomas Bjorn.

WORLD RANKINGS 1 Adam Scott (Aus) 8.94, 2 Henrik Stenson (Swe) 7.78, 3 Tiger Woods (USA) 7.64, 4 Matt Kuchar (USA) 7.03, 5 Bubba Watson (USA) 6.96, 6 Rory McIlroy (N Irl) 6.91, 7 Jason Day (Aus) 6.50, 8 Sergio Garcia (Esp) 6.16, 9 Justin Rose (Eng) 6.05, 10 Jordan Spieth (USA) 6.00, 11 Phil Mickelson (USA) 5.64, 12 Jim Furyk (USA) 5.42, 13 Zach Johnson (USA) 5.24, 14 Dustin Johnson (USA) 4.84, 15 Jason Dufner (USA) 4.50, 16 Luke Donald (Eng) 4.37, 17 Jimmy Walker (USA) 4.28, 18 Graeme McDowell (N Irl) 4.25, 19 Steve Stricker (USA) 4.16, 20 Charl Schwartzel (Rsa) 4.11.

Other Irish in top 100: 74 Shane Lowry 1.89.

Race to Dubai rankings: 1 Thomas Bjorn (Den) €1,470,194, 2 Rory McIlroy (N Irl) €1,295,825, 3 Jamie Donaldson (Wal) €1,233,997, 4 Louis Oosthuizen (Rsa) €1,034,767, 5 Miguel Angel Jimenez (Esp) €956,312, 6 Sergio Garcia (Esp) €931,935, 7 Victor Dubuisson (Fra) €875,354, 8 Stephen Gallacher (Sco) €838,993, 9 Jonas Blixt (Swe) €773,832, 10 Henrik Stenson (Swe) €710,129, 11 Charl Schwartzel (Rsa) €701,428, 12 Lee Westwood (Eng) €667,833, 13 Joost Luiten (Ned) €640,196, 14 George Coetzee (Rsa) €602,002, 15 Shane Lowry (Irl) €560,749, 16 Branden Grace (Rsa) €547,446, 17 Pablo Larrazabal (Esp) €547,375, 18 Alexander Levy (Fra) €528,371, 19 Thomas Aiken (Rsa) €513,310, 20 Tommy Fleetwood (Eng) €498,6010.

Other Irish: 37 Graeme McDowell €322,263, 38 Michael Hoey €307,799, 96 Pádraig Harrington €129,348, 115 Simon Thornton €91,198, 126 Damien McGrane €75,346, 129 Kevin Phelan €68,765, 131 Darren Clarke €68,183, 149 Gareth Maybin €48,483, 154 Paul McGinley €45,169, 162 David Higgins €35,362, 210 Peter Lawrie €12,430, 266 Gareth Shaw €1,547 .