'It's an unbelievable feeling. It's something I've dreamt of for a long time,' said Weir. 'It's a thrill. I have a tough time putting it into words because I probably won't do it justice.'
Mattiace fired an amazing round of seven-under 65 on Sunday to get into the clubhouse at seven-under-par 281. A bogey at the 18th cost Mattiace the outright win but Weir birdied 15 to match Mattiace at seven-under par. Weir parred the final three holes to polish off a round of four-under 68.
Mattiace, playing four groups ahead of Weir and third-round leader Jeff Maggert in the final group, drove right at 18 into the pine needles. He pitched out and played his third over the hole but two-putted for bogey.
'That 18th is a tough hole,' said Mattiace. 'I struggled with it all week. It's just a hard hole. I didn't quite hit the drive solid enough but I felt like laying it up. I still had a good chance for four.'
Weir birdied the 15th to match Mattiace at seven-under par. Weir parred his way in to the force the first sudden-death playoff at The Masters since Nick Faldo defeated Ray Floyd in the 1990 edition.
Weir and Mattiace both found the fairway on the 10th hole, the first extra hole of the sudden-death playoff. Mattiace pulled his approach left of the green and behind a tree while Weir's second landed 45 feet short of the hole.
Mattiace had no choice but to play a low shot right of the tree some 30 feet from the cup. Weir's birdie try ran seven feet past the hole but Mattiace's par-saving putt flew 18 feet past the stick. Mattiace missed that putt for bogey and Weir two-putted for the bogey and his first major title.
'It was a tough grind all week, mentally and physically,' said Weir, who pocketed $1,080,000 for the win. 'I was absolutely beat. I tried to gather myself on each putt. Every putt on this golf course is tough.'
Mattiace, a two-time winner in 2002, broke down after the playoff.
'I gave it my all today,' said Mattiace, whose previous best finish at a major was a tie for 24th at the 1997 U.S. Open. 'The intensity was so high and with the emotions of playing today and executing and shooting a great score, it all just came out.'
Weir earned his third title of 2003 and his sixth since joining the PGA Tour. His closest brush with a major title before this week was in the 1999 PGA Championship. Weir shared the 54-hole lead with Tiger Woods that year but carded a final-round 80 and tied for 10th.
Weir became the first Canadian to win a major championship and only the second left-handed player to earn a major title. Bob Charles captured the 1963 British Open at Royal Lytham & St. Annes.
Woods played a flawless round of 66 in Saturday's third round to get within four shots of the lead with one round to play. On Sunday, he double-bogeyed the third hole after a poor decision off the tee and never recovered, shooting a three-over 75 and tying for 15th at two-over-par 290. In the process, Woods' chances at becoming the first player to win three consecutive green jackets were thwarted.
Woods elected to hit driver at the short par-four third. His ball found the pine needles on the right side and he was forced to hit a wedge left-handed to advance the ball just short of the green. The two-time defending champion pitched his third through the green then left his chip on the fringe with his fourth shot. Woods finally knocked it on the green but missed the putt and left with double-bogey six.
'I made a mental blunder on three,' said Woods. 'I wanted to hit iron. It was a bad decision. Stevie (Williams, Woods' caddie) said it was a better play from down below. I went with it but ultimately it's the player's call and consequently I made the wrong decision.'
For the third year in a row, Phil Mickelson finished in third. Mickelson, the left-hander most would have thought would win a major title first, posted a four-under 68 to come in two strokes shy of the playoff.
'That's better than finishing fourth, I guess, but there's really no consolation out there,' said Mickelson, whose 68 was his lowest final round at The Masters. 'I know that if I just go out and play I'm going to have a shot on Sunday and it's fun to have a chance at winning.'
Jim Furyk carded a four-under-par 68 to take fourth at minus-four. Maggert had a wild round on Sunday with a triple-bogey and a quintuple-bogey but still managed a 75. He took fifth place at two-under-par 286.
It was the customarily wild Sunday at Augusta. The beginning of the round was highlighted by some amazing shots, first by Mickelson at the second. He drove into a hazard at the second hole but dropped and hit driver off the deck to 90 feet. Mickelson holed the astonishing putt for birdie then cracked a wide smile as he inched closer to the lead.
The lead belonged to Maggert but some bizarre circumstances dropped him from first. At the third hole, Maggert drove into a bunker on the left side. His second failed to get over the lip and the ball came back and struck him in the chest, incurring a two-stroke penalty. Maggert triple-bogeyed the hole and never recovered.
'I've been in situations like that where you want to be careful about the ball coming back and hitting your foot,' Maggert said. 'But the way the ball came back and bounced so high, I just heard it hit the lip of the bunker. The next thing I knew, it came back and hit me in the chest.'
The stage then belonged to Mattiace, who collected two early birdies to move up the leaderboard. He chipped in for birdie at the par-five eighth to get to three-under and trail Weir by one shot. Weir went ahead by two with a three- foot birdie at the sixth but Mattiace answered with a long birdie at the 10th.
Mattiace had 224 yards to the flag at the 13th and he nailed his second to 12 feet. He converted the eagle putt to get to minus-six and go one ahead of Weir.
Mattiace took advantage of the next par-five at Augusta, the 15th, when he two- putted from the back fringe for birdie. He went two strokes clear of Weir with that birdie but a seven-foot birdie at 16 gave him a three-shot cushion.
'Masters Sunday is unique in itself. I don't think there's anything like it,' said Mattiace. 'I was in one of those zones. I was in a very good place. I was hitting the shots just the way I was seeing it. That's all you want to do. It was a great feeling doing it.'
Weir also capitalized on the back-nine par-fives. He went through the green with his second at the 13th and his eagle try blew 10 feet past the hole to the fringe. Weir drained that putt to get within two but thanks to Mattiace's error at 18, Weir found himself only one back when he reached the 15th tee.
At the 15th, Weir drove into the left rough and decided to lay up short of the water that guards the putting surface. He wedged his third to three feet and sank the birdie putt to match Mattiace at seven-under par.
Weir parred in but it wasn't without some shaky moments. He left himself with four feet for par at 17 but converted that, then needed a six-footer at the last to force the playoff.
'I wouldn't wish that putt on anybody,' Weir said, referring to the putt at 18. 'If I miss that putt, I three-putted to lose The Masters. I really bore down there and told myself to trust my stroke.'
Ernie Els and Vijay Singh tied for sixth place at one-under-par 287. Scott Verplank (69), David Toms (74), Jonathan Byrd (72), 1998 Masters champion Mark O'Meara (71) and Jose Maria Olazabal (73), a two-time Masters winner, shared eighth place at even-par 288.