Chicago (76-67) at Washington (72-72)

Rico.

The surging Chicago Cubs will try to maintain a share of first place in the NL Central and post their season-high sixth straight win as they open a three-game series with the Montreal Expos in Puerto Rico’s Hiram Bithorn Stadium.

The Cubs equaled their season-high five-game win streak with Sunday’s 9-2 rout of Milwaukee. Chicago also won five straight from May 10-15.

The Cubs are tied with Houston atop the Central, with St. Louis just 1 1/2 games back.

After a three-game sweep of the Brewers, manager Dusty Baker was asked if the Cubs are finally in the midst of the hot streak he had said would eventually come.

“I don’t know yet. We’re in the process,” Baker said. “I’ll let you know whenever it ends how hot it is. But right now we’re in the process. Guys are feeling good.”

Randall Simon homered twice and drove in five runs and Sammy Sosa added a solo shot for the Cubs. Sosa hit his 34th homer of the year and 533rd of his career, one away from tying Jimmie Fox for 11th place on the all-time list.

Cubs outfielder Moises Alou has missed three straight games because of a bruised left knee. He is listed as day-to-day.

Montreal, which lost 3-1 to the Florida Marlins on Sunday, has lost two straight and eight of nine.

The Expos have slipped seven games behind in the wild-card race.

“Our chances are slipping away,” Montreal manager Frank Robinson said. “This isn’t over, but right now we’re not into the fight.”

The Expos have homered in 17 of their 18 games in Puerto Rico.

STANDINGS: Cubs - 1st place, NL Central. Expos - 4th place, 18 1/2 GB, NL East.

CUBS PROBABLE STARTER: Carlos Zambrano (12-9, 2.87 ERA). Zambrano is 6-1 with a 1.46 ERA in his last nine starts. The right-hander gave up two runs and four hits in seven innings, but did not receive a decision as the Cubs beat the Cardinals 4-2 last Tuesday. Zambrano is 0-1 with an 8.10 ERA in three career appearances against Montreal.

EXPOS PROBABLE STARTER: Zach Day (7-6, 3.98 ERA). Day has struggled of late, going 0-2 with a 7.16 ERA in his last three starts. The right-hander allowed five runs and eight hits in five innings of a 5-3 loss to the Florida Marlins on Aug. 31. Day had a rough outing in his first career appearance against the Cubs, yielding five runs, five hits and four walks in 4 1-3 innings of a 6-1 loss on April 8.

OFFENSIVE LEADERS: Cubs - Mark Grudzielanek, .307 avg.; Sammy Sosa, 34 HRs and 92 RBIs; Sosa and Kenny Lofton, 85 runs; Lofton, 29 SBs. Expos - Vladimir Guerrero, .326 avg. and 23 HRs; Orlando Cabrera, 71 RBIs, 87 runs and 22 SBs.

SEASON SERIES: Cubs, 2-1.

STREAKS AND NOTES: Cubs - 1B Simon is batting .281 (16-for-57) with five home runs and 16 RBIs since joining the Cubs. … OF Sosa is 5-for-13 with two home runs, four RBIs and five runs in his last three games. … Chicago has allowed two runs or fewer in six of its last nine games. Expos - OF Guerrero is 2-for-3 against RHP Zambrano. … 3B Todd Zeile has three home runs and five RBIs in his last three games. … Montreal pitchers lead the NL with 13 complete games.

ROAD/HOME RECORDS: Cubs - 39-32 on the road; Expos - 47-25 at home.

INJURIES: Cubs - OF Alou (hamstring), day-to-day; RHP Scott Chiasson (elbow), 60-day DL; LHP Will Ohman (elbow), 60-day DL; CF Corey Patterson (knee), 60-day DL. Expos - C Michael Barrett (hip), 15-day DL; RHP Orlando Hernandez (shoulder), 15-day DL; LHP Scott Stewart (appendicitis), 15-day DL; RHP Claudio Vargas (shoulder), 15-day DL; RHP Tony Armas Jr. (shoulder), 60-day DL; RHP Dan Smith (shoulder), 60-day DL; 3B Fernando Tatis (chest), 60-day DL.