FULLERTON, Calif. >>

The hard part is over for Hawaii. All the Rainbow Warriors have to do now is beat three teams in three days.

Sixth-seeded UH — the only team this NCAA Division I season to go 1-1 against every league opponent — gets defensive stalwart UC Irvine, the third seed, at 4 p.m. (HST) today in the Big West tournament first round at the Honda Center in Anaheim.

Thanks to a combination of inconsistency and parity, the ’Bows (17-12, 8-8) became the first team in program history to go 1-1 against all comers in conference standings.

“I look at it more as positive than a negative, because we’ve proven we can beat everybody,” point guard Brocke Stepteau said. “In big games, we’ve proven we can bring our best.”

UH has remained around its base of operations at the Marriott on the Cal State Fullerton campus. The ’Bows practiced the last two days at nearby Fullerton College, which was their lead-up site two years ago when they won it all.

When UH defends at a high level, it gives itself a chance to beat anyone in the Big West. When it doesn’t, it doesn’t win. The numbers are stark: BWC opponents shot 38.7 percent in UH’s victories, and 52.1 percent in its losses.

Irvine (16-16, 11-5) knows all about defending at a high level to eke out wins. It’s allowed 38.9 percent shooting by opponents for the full season, fourth in the country, with a plus-7.9 rebounding margin, which ranks eighth. UH shot 35.2 and 34.6 percent, and actually claimed the boards once, in the split home-and-home series that saw each win on the other’s home floor in the last three weeks.

“The size and the depth of the size, and even the depth of the overall team,” UH coach Eran Ganot said of UCI. “They’re probably the gold standard in terms of the defending and rebounding end. … I think there’s a mutual respect there.”

Since shooting 16-for-30 in the first half at Bren Events Center on Feb. 15, UH was 21-for-76 (27.6 percent) in the next three periods of the series. UH somehow held on to win 62-61 at the Bren shooting 3-for-24 in the second half.

The ’Bows know they’ll probably have to win ugly. To do that, they’ll have to match the Anteaters’ toughness throughout without fouling excessively.

“Happy that we have Irvine. A big game,” said co-captain Mike Thomas (13.0 ppg, 6.0 rpg). “You don’t want it easy in these moments. You want to win against the best teams.”

Irvine, which slipped to third after a gut-wrenching 90-84 double-overtime loss to UC Davis in the de facto regular-season championship on Saturday, is 2-0 under Russell Turner against UH in the tournament. They beat Gib Arnold’s group in the 2013 first round and Benjy Taylor’s bunch in the 2015 title game.

“Hopefully we can be a little edgy coming off a defeat, which is not always bad,” Turner said this week. “Last time we won this tournament, we had the same feeling. We lost to Davis the last game of the regular season and went to the tournament as a 3 seed. So we feel like we have some reason for optimism. … We know the chips are down.”

Sophomore forward Tommy Rutherford (10.5 ppg, 5.8 rpg), a Big West first-teamer, leads UCI’s stable of big men on offense, but it’s two-time BWC defensive player of the year Jonathan Galloway (7.7 rpg) who changes the game on D with his mobility at 6 feet 10.

“He can really guard inside and outside, which is pretty unique,” associate head coach Adam Jacobsen said. “He’s usually matched up with Mike Thomas and Jack Purchase (7.6 ppg), two of the better offensive players on our team. So, that matchup is definitely big and sets the tone for their team.”

UH tried to simulate it by having Mate Colina, a 6-11 redshirt freshman, play extra physical during scout preparation alongside 6-10 center Ido Flaisher.

Patience, too, is required, as multiple sets in the same shot clock are often needed to crack the Anteaters’ alternating man and zone formations.

You can’t sleep on UCI’s O, though.

Guard Evan Leonard, a BWC second-teamer, averaged a team-high 15 points in the two meetings against UH, while his backcourt mate Eyassu Worku (11.1) was held in check. John Edgar Jr. (8.5), a husky wing, had a thunderous dunk over Gibson Johnson (9.9) in the Feb. 24 rematch in Honolulu, won 66-57 by the ’Eaters.

The UH guard rotation took a potential hit in the regular-season finale at Cal State Fullerton when Leland Green (5.7) went out late with a right shoulder injury. However, the sophomore has bounced back and seems probable to play today. Drew Buggs (8.1), Stepteau (9.6), Sheriff Drammeh (10.8), and Brandon Thomas (1.9) look to pick up the slack if he can’t.

“There are no excuses,” Ganot said. “Hopefully we’ll continue to feel strong the next 24 hours before the game.”