San Jose Earthquakes The next season, when Canadian
Frank Yallop was named head coach of the
San Jose Earthquakes, De Rosario was one of his first acquisitions. De Rosario proved Yallop's judgment right, scoring five goals and four assists in only 1,072 minutes for the Earthquakes in 2001, playing an important role as the team went on to win the
MLS Cup; he scored the
golden goal in the final and was named MLS Cup MVP. De Rosario had similar success in 2002, registering four goals and eight assists in 1,637 minutes, though the Quakes fell short of a repeat. In 2003, a torn ACL hobbled De Rosario for much of the season but he still managed to make a late surge, registering four goals and three assists in only 686 minutes and helping lead the team to a second MLS Cup championship. De Rosario played 1,211 minutes in 2004, scoring five goals, including the 2004
MLS Goal of the Year, and three assists. In December 2004 De Rosario had a trial with
Nottingham Forest, but he was not offered a contract by the team. In 2005, following
Landon Donovan's departure, De Rosario moved to midfield and promptly led MLS in assists with 13, while scoring nine goals, including the 2005 MLS Goal of the Year – the only player ever to receive that honour in two consecutive years – for a powerful bending free kick in the last regular season game against the
Los Angeles Galaxy. He was named to the
MLS Best XI six times (2005–07, 2009–11). The next year, De Rosario assisted on
Joseph Ngwenya's equalizing goal and scored the winning goal of the
2007 MLS Cup final, giving Houston a 2–1 win over the Revolution and the Dynamo their second championship. De Rosario was named MLS Cup MVP, the first player ever to win the award twice. De Rosario made his third consecutive all-star appearance at the
2008 MLS All-Star Game in his home country, when the game was held in Toronto. He scored the decisive goal on a penalty kick in the 69th minute in the MLS All-Stars' 3–2 victory over
West Ham United.
Toronto FC De Rosario was traded to
Toronto FC on December 12, 2008, in return for
Julius James and allocation money, after long speculation that De Rosario would move to his hometown club. He made his competitive debut for Toronto FC on Saturday, March 21 against the
Kansas City Wizards, setting up
Jim Brennan for Toronto's first goal in a 3–2 victory. He scored his first goal for Toronto from a header in a 1–1 draw at BMO Field against FC Dallas. De Rosario was expected to miss the first two to four weeks of Toronto FC's training camp due to a calf injury obtained in the January 31, 2010, match against Jamaica, and returned to game action in Toronto's 1–0 preseason win versus the
University of South Florida. On April 8, 2010, De Rosario was named
captain of Toronto FC, the second in the club's history, after the retirement of
Jim Brennan. Two days later, De Rosario scored his first goal of the
2010 season, his team's first, in a 4–1 loss to the
New England Revolution. On April 15, 2010, De Rosario scored twice in Toronto's 2–1 home opener win against the
Philadelphia Union. In his next game versus the
Colorado Rapids, De Rosario scored his fourth goal of the season, and more importantly, became Toronto FC's all-time leading scorer in the regular season. De Rosario again found the back of the net on April 25 in a 2–0 home win against
Seattle Sounders FC, scoring the first goal, his fifth of the season. Until
O'Brian White scored the second goal for Toronto, De Rosario had previously scored all of Toronto's goals up until that point in the season. For his efforts in that game, he was awarded the MLS Player of the Week for week 5. De Rosario was again honoured with the Player of the Week award on week 10 of the MLS season, for his two-goal performance against his former team the
San Jose Earthquakes. De Rosario had scored the second and third goal in Toronto FC's 3–1 win. De Rosario continued to have a successful 2010 season for Toronto, culminating in a spot on the MLS All-Star team, scoring a goal in the
5–2 loss to
Manchester United. On August 3, 2010, De Rosario scored against
C.D. Motagua in the second leg of Toronto FC's
CONCACAF Champions League preliminary round tie, which at the time, put TFC ahead on 2–1 on aggregate. They would eventually win 3–2 on aggregate. On December 28, De Rosario was confirmed to be on trial with
Scottish Premier League club
Celtic by manager
Neil Lennon. Dwayne and Celtic inquired about the possibility of a short-term loan deal until the MLS season kicked off in March, however new Toronto FC coach
Aron Winter and the league denied any further negotiations. De Rosario scored the first Toronto goal of the 2011 season on March 19 in a 4–2 away defeat to
Vancouver Whitecaps FC in what was the league's first all Canadian match up. The goal scored in the 20th minute was also the 8000th goal scored in Major League Soccer's history.
New York Red Bulls New York Red Bulls acquired De Rosario on April 1, 2011, in exchange for midfielder
Tony Tchani,
Danleigh Borman and a first round
2012 MLS SuperDraft pick. He scored his first goal for New York on a penalty, as the second goal, in a 3–2 loss to
Chivas USA.
D.C. United D.C. United acquired De Rosario on June 27, 2011, in exchange for midfielder
Dax McCarty. He scored his first goal for the club against his former club
New York Red Bulls on his return to
Red Bull Arena. On July 30, 2011, his double gave United a 2–0 victory over former club, San Jose. On August 6, 2011, he led United to a 3–3 draw against Toronto F.C. with his hat-trick. All three goals were scored while United played with ten men following an early ejection of goalkeeper Bill Hamid. His second hat-trick was recorded on September 25, 2011, as he recorded all three goals in the span of 9 minutes, setting another MLS record. De Rosario completed the season with a total of 16 goals and 12 assists over 32 games. Of those, 13 goals and 7 assists were made during his 17 games with United. On August 29, 2012, De Rosario scored his 100th MLS goal, in a 2–2 home draw against the Red Bulls. He was the seventh player to reach the milestone.
Return to Toronto FC After having his option declined by D.C. United, De Rosario returned to Toronto FC on December 18, 2013, after being chosen in the
2013 MLS Re-Entry Draft. He officially signed with the club on January 9, 2014. It was announced on December 3, 2014, that Toronto had declined the option to renew De Rosario's contract. De Rosario announced his retirement on May 10, 2015, and that he would be taking an ambassador role with
Maple Leaf Sports & Entertainment, the owners of Toronto FC.
Mississauga MetroStars In October 2018, De Rosario came out of retirement at age 40 to sign with the newly formed
MASL club, the
Mississauga MetroStars, as captain and assistant coach. He sought to earn his "A" coaching license while with the club and was approached by the MetroStars general manager after playing for the Canada arena soccer national team in March. De Rosario scored his first goal for the club in the MetroStars's opening match, an 11–3 loss away to the
Baltimore Blast. The team folded before the start of the 2019–20 season due to issues finding a permanent home venue. == International career ==