MINNEAPOLIS, JULY 5 -- Another winnable game became another loss for the Baltimore Orioles this afternoon when Kent Hrbek led off the bottom of the ninth inning with his 22nd homer to give the Minnesota Twins a 4-3 victory before 21,294 at the Metrodome.

Hrbek hit the homer off Orioles reliever Tom Niedenfuer and it wasn't the first big one off him. A week ago today, he gave up three in a row to get the Detroit Tigers back into a game and, in 22 games since joining the Orioles, has allowed eight in 24 innings.

Still, this was an even bigger one because it beat the Orioles on a day when their pitching was good. Dave Schmidt pitched seven good innings and left "because he was completely out of juice," Orioles Manager Cal Ripken Sr. said.

It's also a big one because today marked the halfway point of the season, and, at 31-50, the Orioles are on a pace to lose 100 games, something they haven't done since 1954, their first year in Baltimore.

"We've got a tough row to hoe," Ripken said. "I'll say this: We're going to keep working and trying, but it doesn't look too good right now. We got a well-pitched game from Schmidt, then couldn't hold it."

A night earlier, Ripken had moved rookie Mark Williamson back to the bullpen because he needed a setup man for Niedenfuer. Now, Williamson may be the setup and short man.

Asked if he were close to giving up on Niedenfuer, Ripken said: "It looks like we're going to have to find someone else. The ball goes that far out and is hit that hard, it can't be a good pitch. He's been a disappointment. That's clear when you keep bringing a man in to hold a lead or a tie, and we keep getting beat, anyway."

Niedenfuer refused to talk after the game, saying only "not today."

In losing for the 30th time in 35 games and the eighth time in nine games on this road trip, the Orioles got nine hits off Bert Blyleven (8-6) and came back for ties after deficits of 2-1 and 3-2.

Schmidt allowed three runs on four hits in seven innings, but, after the seventh, went to Ripken and said he couldn't go on. He'd thrown only 81 pitches, but had been used in relief once since his previous start.

"He did fine," Ripken said. "All we ask of our starters is to give us six or seven innings and keep us in the game. He did that."

The Orioles returned to Baltimore tonight and will play seven home games before the all-star break. General Manager Hank Peters said more roster moves are being considered as the Orioles, 19 1/2 games out of first, start looking toward 1988.

Ripken had been thrown out of Saturday's game for arguing a strike call by plate umpire Tim Tschida, and the Orioles had more umpire trouble today, the biggest coming in the sixth when plate umpire Nick Bremigan threw out Fred Lynn for arguing a strike call.

Lynn had to be restrained from going after Bremigan and was finally ushered back to the dugout, much as Ripken had been 24 hours earlier.

"All I said was that the ball was low," Lynn said, "and the next thing I knew he was in my face. He also cussed me, and when that happens you're into something besides balls and strikes. When I went to the dugout, he was looking at me. I said, 'Get your head in the game,' and he threw me out."

Bremigan said: "He had his say and I had my say. I thought that was it, but he had something else to say in the dugout."

The Orioles led early, going up by 1-0 off Blyleven in the second when Larry Sheets singled and scored on Ken Gerhart's double. The Twins came right back for a 2-1 lead in the last of the second when Gary Gaetti got a one-out double, Roy Smalley walked and Steve Lombardozzi tripled to the wall in left-center. Murray's 15th homer tied it 2-2 in the fourth, and Sal Butera's first homer gave Minnesota a 3-2 lead in the fifth.

The Orioles again came back, tying it in the seventh when Rick Burleson doubled down the line, went to third on on a wild pitch and scored on another.

Niedenfuer held the tie in the eighth, but Hrbek led off the ninth by hitting a 1-1 fastball 420 feet.

"I was going up there to hit the ball hard," Hrbek said. "It's not often that you go all out and you hit the ball out of the park. Sometimes you overswing. But I was going up there to hit that way."

Orioles Notes:

When Tschida heard himself being criticized by a Minneapolis sports columnist on a radio show this morning, he phoned the show to give his side of the argument with Ripken. Instead, he ended up in an argument with the show's host . . . Murray's homer was the 27th off Blyleven this season. He allowed a major league-record 50 last season . . . In the past 12 games, the Orioles' first two hitters in their batting order have a .198 on-base average and .140 batting average, which doesn't leave many RBI chances for Cal Ripken Jr. and Murray . . . Left-hander Chris Myers, the Orioles' first choice in the June draft, made his professional debut last night. Starting for Bluefield in the rookie Appalachian League, he went four innings, allowing an infield hit and a walk and striking out four. Bluefield beat Elizabethton, 5-3.