Keeping it going could prove difficult in Houston, where the club hasn't seen much go its way.
Dallas tries to snap its road woes against the Dynamo as these in-state rivals meet Saturday night with El Capitan on the line.
Diaz scored the go-ahead goal in the 84th minute in a 2-1 victory over Portland last Saturday. Dallas (3-0-1), which hadn't earned 10 points through its first four games since 2006, has never gone unbeaten through its first five.
"We've started well and we're happy," first-year coach Oscar Pareja said. "We know where we are and we don't want to think too much about what we have not done before. We're developing a culture of taking it one game at a time, without giving importance to what happened last season or what will happen."
Diaz has been terrific thus far with two goals and an assist. The Argentina native had three and two, respectively, in 10 games last season, his first in MLS.
"To come and perform that way, it shows all the sacrifices he has put in, so that is fantastic," Pareja said of Diaz, named MLS player of the month for March. "This is recognition to his teammates who are doing a fantastic job with him."
While FCD pulled out a thrilling 3-2 home win over the Dynamo in last season's only league matchup after scoring in the 90th minute, a repeat performance could be hard to come by on the road. Dallas is 1-7-3 all-time in Houston.
"We get to go on the road with a tough challenge, but we're up for it," goalkeeper Chris Seitz told the team's official website. "We've gone into tough places, played well and gotten points out of it. We're going to go down and look for three."
Dallas is hoping to hold on to El Capitan, a replica 18th century cannon given to the winner of this rivalry.
"That thing's probably not easy to move, so we're going to look to keep it here," FCD defender Stephen Keel said.
Houston (2-1-0) has its sights set on the cannon, too.
"I think as players we try to downplay it a little bit as a rivalry, but if I'm going to tell you the truth, I enjoyed when we had El Capitan," goalkeeper Tally Hall told the Dynamo's official website. "I enjoy having the rivalry. I enjoy the storylines. ... I think it's fun."
Houston opened the season with back-to-back home wins over New England and Montreal before falling 2-1 at Vancouver last Saturday. The Dynamo fell behind 2-0 before Ricardo Clark scored in the 75th minute.
"You always feel like if you go on the road and didn't get the results you want, coming back home you want to secure those points and if you get the maximum points at home then you do pretty well in MLS," striker Omar Cummings said. "Especially seeing that it is Dallas, it's a rivalry. ... Fans get into it and it makes it a really interesting game."