PORTLAND, Ore. (AP) — An undefeated season, 20 consecutive victories and that No. 3 ranking aside, the Gonzaga Bulldogs think they can be better.

Zach Collins had 13 points and Gonzaga remained the nation's only undefeated Division I team with an 83-64 victory over Portland in a game Monday night that was rescheduled because of a winter storm earlier this month.

"I think if we reach our potential and continue to get better each week, day-to-day, obviously I think we have the talent and the ability to get to the Final Four," guard Nigel Williams-Goss said.

Gonzaga's 20-game winning streak is the fourth longest in school history, matching runs in the 2005-06 and 2003-04 seasons. The Bulldogs are now 8-0 in West Coast Conference play.

Silas Melson and Jordan Mathews each added 12 points for the Zags, who led by as many as 33 points and had four players in double-digits.

Rashad Jackson and D'Marques Tyson had 15 points apiece for Portland, which won its first two games in conference but has lost six straight since then. The Pilots (9-11, 2-6 WCC) are playing their first season under former NBA player and coach Terry Porter.

The game was originally scheduled for Jan. 7, but a winter storm in Portland forced it to be postponed. Portland opened up extra seats for the sellout and Gonzaga's fans outnumbered the home team's crowd.

The two teams had met just two days ago in Spokane, with Gonzaga leading from the start to win 73-52. But Portland, playing without top scorer Alec Wintering, out-rebounded the Zags 41-33 and held them to 45 percent shooting.

The Zags fared better on Monday, out-rebounding Portland 41-36 and shooting 52 percent.

Williams-Goss, who left Saturday's game against Portland because of a left hip injury with about five minutes left, was questionable against the Pilots on Monday but started. He finished with four points, off his average of 15.

"A little sore, but it's to be expected. It was such a quick turnaround, I didn't have a lot of time to recover," he said.

Wintering, a senior, was hurt in last Thursday's game against San Francisco and the Pilots announced this weekend that his college career was over because of a torn left ACL.

Wintering averaged 19.5 points and 5.6 assists a game this season. He was on Portland's bench in street clothes, but during warmups before the game and at the break he was on the court, offering his teammates advice and encouragement.

"Obviously we've been looking at some different guys and have been looking at some different lineups. So were using the time really to take a long look at our guys and try to see what they are," Porter said. "We're trying to give them an opportunity big picture."

Gonzaga jumped out to a 9-0 run but the Pilots closed within 9-8 following Philipp Hartwich's dunk. Portland was competitive, answering Melson's 3-pointer for Gonzaga with Jackson's 3 that got the Pilots within 22-19.

But the Bulldogs responded with an 8-0 run to go up 30-19 and went into halftime with on a 16-4 run for a 38-23 lead. Melson and Jonathan Williams led Gonzaga at the break with eight points apiece. Jackson's 13 first-half points for Portland were a new career high for a game.

Gonzaga extended the lead to 50-26 on Przemek Karnowski's layup with just under 16 minutes to go, the Bulldogs were on the way to their 20th straight win.

THE BIG PICTURE

Gonzaga: The Zags have won eight straight against Portland. ... The Bulldogs' longest winning streak was 22 games, set in the 2014-15 season.

Portland: Portland Trail Blazers President Neil Olshey was at the game. ... The game, originally scheduled to be played over winter break, was sold out. So despite school being back in session, the usual student section wasn't as large for the televised game.

POLL IMPLICATIONS: Gonzaga rose a spot from No. 4 and only trails No. 1 Villanova (19-1) and No. 2 Kansas (18-1) in the AP rankings released earlier in the day. The Bulldogs were also ranked No. 3 in the Feb. 23, 2015 poll.

TILLIE INJURED: Gonzaga Freshman forward Killian Tillie injured his right ankle under Portland's basket with 9:38 to go in the game, and teammates helped him from the floor. The 6-foot-10 Tillie, who is from France, is averaging 4.8 points this season.

"It looks to me like a pretty good ankle sprain right now," Gonzaga coach Mark Few said. "We'll have to get it fully evaluated once we get back home."

HOMETOWN CROWD: Williams-Goss played high school basketball in Nevada at Findlay Prep, but before that he lived in Happy Valley, outside of Portland.

"Nigel's a tough guy and he's such a good competitor. He certainly wasn't at full strength, but he wanted to play, especially being from down here, and he did a nice job stepping up and competing," Few said.

UP NEXT

Gonzaga: Gonzaga hosts San Diego on Thursday night.

Portland: The Pilots visit Pepperdine on Thursday night.