MONTREAL (AP) -- Geoff Blum made the most of a rare start.

Blum matched his career high with three RBI, including a two-run homer, and Vladimir Guerrero hit his 16th home run as the Montreal Expos beat the Baltimore Orioles 7-4 Saturday night for their fourth straight victory.

"When you're sitting on the bench for a couple of games here and there and you don't get too many opportunities, you've got to take advantage of them when you get in there," Blum said.

Baltimore lost its 19th straight game in Canada despite a two-run homer by Albert Belle and back-to-back homers in the fourth by B.J. Surhoff and Charles Johnson.

Blum, starting at second base in place of injured Jose Vidro, hit an RBI double in the third and homered in the fifth off Pat Rapp (4-3) to raise Montreal's record at Olympic Stadium to 20-9.

"The team can't wait to get home," Expos manager Felipe Alou said. "The wish, for all of us, is that home continues to be home the rest of the year."

Blum echoed Alou's statement.

"It's our house," Blum said. "When people come in we want to beat them at our house. When we come home we expect to win, we want to win. These are the games that we need to win."

Expos starter T.J. Tucker, called up from Double-A Harrisburg to make an emergency start, allowed four runs and six hits in four innings.

Montreal reliever Felipe Lira (1-0) didn't allow a run despite facing seven batters in one-plus innings for his first NL win. Lira allowed two hits and walked two.

Steve Kline pitched the ninth for his third straight save, and fourth in five chances, to send Baltimore to its fourth straight loss.

Vidro missed his first start of the season due to a sprained ligament in his right middle finger.

Montreal raised its record to 28-23 in interleague play, including 18-7 at home.

Alou believes that there is an advantage in hosting AL opponents.

"There has to be something," Alou said. "The adjustment to the ballpark, and so forth, and so on."

Belle homered for the second straight game, a two-run shot in the third, his eighth home run of the season.

Tucker got an infield single in his first major league at-bat leading off the third and scored on Peter Bergeron's triple as Montreal closed to 2-1.

Surhoff's homer tied it in the fourth and Johnson's homer put Baltimore ahead 4-3. Blum's second homer of the season gave the Expos a 5-4 lead in the fifth.

Rapp allowed nine hits and five runs in five innings.

"The only runs we could put across the plate were on home runs," Rapp said. "Three jacks for four runs and we had men on base a bunch of times but we just couldn't put them across. Every time we had a lead I just never held it."

Guerrero hit a solo homer in the seventh off Al Reyes and Orlando Cabrera connected in the eighth off Mike Trombley.

Game notes
Orioles manager Mike Hargrove missed the game and will also miss Sunday's series finale in order to attend his son Andy's high school graduation in Cleveland. Bench coach Jeff Newman is substituting for Hargrove. ... The Orioles are 12-25 since April 22, when they were a season-high six games over .500. ... Belle has hit safely in 27 of his last 30 games, going 38-for-115 (.330) over that stretch. ... SS Mike Bordick has started each of Baltimore's 53 games. ... Blum drove in three runs last Sept. 15 at Los Angeles. ... Vidro, who injured his finger two weeks ago while diving back to first base, received a cortisone shot before the game and is expected to miss three games. ... RHP starter Mike Thurman was given a cortisone shot in his injured right elbow Saturday. Thurman is on the 15-day disabled list because of tendinitis for the second time this season.