BOSTON, JUNE 23 -- For the Baltimore Orioles, the end of a game does not get much worse than this.

Leading by one run with two out, none on and Gregg Olson pitching in the 10th inning, they lost to the Boston Red Sox, 4-3, today at Fenway Park when Tom Brunansky hit a full-count pitch for a single then Dwight Evans hit a 2-2 pitch over the Green Monster.

It was the first home run Olson has allowed since April 15, 1989. That also was by Evans over the Green Monster.

"That's about the toughest way we can lose a ballgame," said Manager Frank Robinson, whose team is 1-4 on a six-game road trip, with all four losses by one run that their opponents scored in the seventh inning or later. "All losses hurt, but this one is going to be very, very difficult to digest."

Evans was the last batter to have homered against Olson -- 115 innings and 479 batters before he came to the plate today with pinch runner Randy Kutcher on first.

The Orioles had failed to take advantage of numerous opportunities to prevent the game from coming down to this. Even after Mickey Tettleton hit a bases-empty homer off reliever Rob Murphy with one out in the top of the 10th, the Orioles put runners on first and second. But Joe Orsulak was thrown out on the front end of a double steal and Craig Worthington struck out after Bob Melvin walked to become Baltimore's 19th base runner of the game.

The Orioles took a 2-1 lead on second baseman Jody Reed's two-out fielding error in the eighth. But with two out and none on in the bottom of the inning, Evans hit a homer off starter Dave Johnson. It was Evans's first home run since June 3 and first here since April 28.

"It's driving me nuts," said Johnson, who outpitched Boston starter Roger Clemens for the second time in five days.

Olson's first pitch to Evans bounced past Tettleton, who made several nice blocks to preserve a save in Olson's last appearance.

With Kutcher on second after the wild pitch, Evans took the next pitch, which umpire Mark Johnson called a strike -- much to Evans's displeasure. After another ball, Evans could not check his swing on a pitch out of the strike zone. Olson's next pitch was a fastball, also out of the strike zone, but Evans fouled it back. Olson came in with another high fastball.

"I was just trying to get a piece of it and hit it somewhere to get the man home from second," Evans said.

"I was happy he was swinging at it," Olson said. "More guys will strike out on that pitch than put the ball in play. When he started swinging at it, I thought I had him."

Instead, Evans sent the ball zooming to left. It landed high in the net that extends 23 feet above the 37-foot wall.

Evans said he was thinking curveball on the pitch, but Robinson rejected that thesis. "There's no way he was looking for a curveball with the way he hit that fastball," Robinson said.

"I'm not going to second-guess myself on the pitch," Olson said. "Brunansky also hit a good pitch. What am I going to say? They beat me."

That has been happening frequently lately with Olson, who also went through a two-week slump last July. In seven appearances during that stretch, he blew four of five save opportunities and was 0-2 while allowing six runs on 12 hits and 10 walks in nine innings. The Orioles went 4-10 while Olson struggled.

This time, he has blown two of three save opportunities since June 7. In three appearances on this road trip, he has blown one of two save opportunities, compiling an 0-2 record and allowing three runs on six hits and one walk in 2 2/3 innings.

"People are going to put it together and say I'm going bad," Olson said. "I don't think I am. It hasn't gone completely bad."

It has come close -- for him and for the Orioles. They have lost nine of 11 and 10 of 13. They have fallen to sixth in the AL East. And their loss today, combined with first-place Toronto's victory over New York, dropped them 8 1/2 games back.

"It's still so early," Olson said. "We can't panic."

Robinson said after Friday night's game: "No team's going to run away with this thing. The only thing I'm concerned with is way this team is playing. I know with our division if we play some good baseball, we'll be right in the thick of things."

But before today's game, he said: "We need this one -- for the trip. If we can win today, we have a chance for three wins, which would make it a decent road trip. If we lose today and lose tomorrow, it would be a terrible trip."

Clemens and Johnson also were the starters Monday in Baltimore when the Orioles won, 7-2, as Johnson pitched a nine-hitter and Clemens lasted 1 2/3 innings -- his earliest knockout since August 1988.

Clemens struggled again today while Johnson performed the way he has all season.

After allowing a run on three hits in the first, Johnson did not allow more than one base runner in an inning until the eighth. In his last nine starts, he has allowed 22 earned runs in 59 2/3 innings to lower his earned run average to 3.96.

Clemens threw 138 pitches in nine innings and allowed two unearned runs on six hits and a season-high five walks. He benefited considerably from four double plays, but walks and errors did him in.

A fielding error by shortstop Luis Rivera, a walk, and a fielding error by third baseman Wade Boggs allowed Baltimore to tie the score at 1 in third on a double-play groundout by Randy Milligan. A walk to Tettleton in the eighth became the go-ahead run on Reed's miscue.

Orioles Notes: Shortstop Cal Ripken, who played his 66th consecutive errorless game (three shy of Mark Belanger's club record), had his third consecutive three-hit game. He is 10 for his last 13 and his batting average is up to .245. In his last 10 games he is batting .439. . . .

Outfielder Brady Anderson, on the disabled list since June 9 because of a sprained left ankle, is not expected to be activated for "at least a couple of weeks," trainer Richie Bancells said.