Oregon State may have scored the first bucket of the night, but Washington tied it up in far more memorable fashion when Thybulle caught a pass on the perimeter, saw the shot clock dwindling, and split two defenders for a huge dunk.
The Beavers again scored at the rim to claim the lead but on the next possession Chriss soared to catch a lob pass with one hand and hammer it home to make it 4-4.
Eubanks finished through Malik Dime and earned a three-point opportunity with 16:05 left in the first half. He hit the free throw to make it 6-11 in favor of the Beavers.
Schaftenaar hit a transition three off an Andrews miss in the lane to give the Beavers a 12-2 run.
After a timeout Andrews stopped the bleeding by draining a deep three of his own. Payton II answered with an even more difficult rainbow of a shot from beyond the arc, but the Andrews followed with yet another salvo to give the Pac-12 leading scorer six points.
At the TV timeout taken with just under 11:41 left the half Oregon State led 25-14, defense once again being a glaring issue for the Huskies.
Just over a minute later Andrews jacked up a deep three through contact in the final moment of the shot clock. He hit the shot and the ref declined to give him the call. David Crisp hit a transition three on the very next possession to cut the lead to two.
Oregon State responded with four straight points to establish a 29-23 lead with just under nine minutes in the half.
Eubanks scooped up an easy offensive rebound and put it back for his eleventh points of the night. Chriss responded with a corner three only to have Thompson Jr. answer within seconds.
Both teams continued to trade blows until Murray scored a highlight-reel spinning layup to make it 33-38 with five minutes left.
At this point ESPNU lost the broadcast, depriving the home audience of a Dejounte Murray run. He scored several times in quick succession, capped off with a three-pointer to claim a 42-41 lead with 2:11 left.
The Beavers responded with six straight points, first a Tinkle three and then a three-point play from Thompson Jr.
Chriss hit his second trey of the night to respond and Tinkle followed up with a layup on the other end with under a minute in the half.
Andrews tried for his fourth three of the night but it rimmed out, giving the Beavers a few seconds to set up Shafternaar for a deep miss of his own.
The Huskies trailed 49-45 at the half thanks to a strong offensive show from the home team, including 13 points and 7 rebounds from Eubanks, 10 points from Thompson Jr., and 9 points each from Payton II and Tinkle. The Beavers shot 20-34 from the field and out rebounded Washington 15-9.
Washington just about kept up thanks to hot 8-14 shooting from beyond the arc and a late flurry from Dejounte Murray, who led the team with 11 halftime points.
Dime started the second half with an easy two-handed dunk. On the other end Dime's poor defense allowed Eubanks a two-handed slam of his own.
Murray coughed up a careless turnover with 16:30 left then seconds later stole the ball back and dished to Dickerson for a fast break dunk.
Oregon State committed an offensive foul just before a TV timeout with 15:45 left and the Beavers leading 53-49.
Chriss broke a long dry spell for both teams by skying over multiple players to put back an errant Andrews three with his right hand. It was perhaps the fourth or fifth Washington play worthy of a highlight reel.
After a relatively foul-free first half Washington racked up five fouls in the first eight minutes of the second half. Tinkle hit two free throws to extend the Oregon State lead to 56-51.
Andrews pulled up and nailed his fourth three of the night to cut the deficit to one with 12:25 left. The parade of fouls continued, however, with Dime picking up his fourth and exiting the game.
Andrews responded to picking up his third foul via a cheap whistle by going coast to coast for a layup only to see Chriss tagged with his second personal on another questionable call.
A barrage of scoring from both teams concluded with a violent Payton II dunk and a transition hustle basket from Jarmal Reid to force a Washington timeout, the Huskies trailing 66-60 with 9:56 remaining.
With the deficit up to 8 and the Huskies starting to fade, Andrews skipped into the lane and created a three-point play and followed with a difficult fadeaway jumper from mid-range to bring the Huskies within one point.
Chriss picked up his fourth foul just before a TV timeout suspended play with 7:53 minutes to play.
Coach Tinkle elected to go with a zone defense out of the timeout but Murray beat it immediately, hitting a tough floater and earning a whistle for a chance to take the lead. Dejounte missed, leaving the game tied 69-69, and after an OSU turnover Crisp earned a trip to the line and went ahead and missed both of his attempts.
Jarmal Reid, apparently feeling some sympathy for the Huskies, clunked both of his free throw tries on the very next possession, giving Andrews the chance to drain a very deep three to claim a 72-69 lead in dramatic fashion.
Dime fouled out on a soft call that allowed Thompson Jr. to hit two shots and tie the game 72-72.
Murray heaved up an air ball with the shot clock down to a few seconds. Payton II drew a foul on Thybulle seconds after but the star guard missed both tries to keep it tied.
Murray cut into the paint and banked it in beautifully to retake the lead with under three minutes to go.
On the following possession Andrew Andrews stepped in to a three from several steps behind the arc and dropped it in to give the senior 27 points and put Washington up five.
OSU trimmed the deficit to four by hitting a free throw, then a characteristic soft call on Payton II put Andrews on the line. He hit both to make it 79-73 with 1:48 left.
The Beavers were given some life by a Eubanks put-back. Coach Tinkle called timeout down four points with 57 seconds to work with.
Tinkle came up huge, hitting a desperation jumper from the corner with a Husky defender leaning into his chest. It was initially called a three but review spotted his toe on the line.
Oregon State fouled Crisp with 20.5 seconds remaining. Crisp only hit one of two, giving the Beavers a chance to force overtime on one final possession.
An errant pass deflected off of Murray, allowing Tinkle to take timeout to draw up one last play with 7.8 seconds left and Washington clinging to an 80-77 lead.
Crisp fouled Tinkle just before he attempted a three, meaning two shots with 5.3 seconds on the clock. He hit both and OSU elected to foul Andrews.
Washington's senior leader hit the first to give himself 30 points on the night, then missed the second to give Oregon State the ball and 3.1 seconds to score.
Thompson Jr. drained a three at the buzzer to steal the game 82-81. He clearly took several extra steps just before launching the faithful shot, but the officials ignored the travel and the Huskies are effectively banished to the NIT barring a Pac-12 tournament championship.
Blame the refs for missing a comical walk. Blame Andrews for missing the second free throw. Blame the whole team for playing putrid defense all night.
I suppose the healthy choice is to tip your cap to Thompson Jr. for a great shot, but it's simply a punch in the gut no matter how you choose to process it.
Andrews finished with 30 points, Murray with 15, and Chriss with 14.
A trip to Eugene looms on Sunday.