The Sunwolves scored three-first half tries but were unable to hold onto the lead Saturday, losing a heartbreaker to the visiting Queensland Reds 34-31.

Playing in front of a full house at Prince Chichibu Memorial Rugby Ground, the Sunwolves took a 21-5 lead into halftime, but missed out on their first home victory of the season after allowing the visitors to mount a late comeback.

Indiscipline again proved costly for the Tokyo-based side — which was penalized 11 times, while the Reds conceded just four — as fullback Hamish Stewart converted a last-minute penalty to seal the win, the first of the season for the Brisbane-based side.

"I think comparing the first half and the second, I think it was just the lack of technique, and the way we were playing in the second half was different from how we were in the first half," said Sunwolves fullback Jason Emery. "They started getting momentum and more confidence."

The Sunwolves opened the match as favorites, having beaten the Reds 63-28 at the same stadium last year. And despite a creaky set piece they dominated the opening 40 minutes.

Scrumhalf Jamie Booth put the hosts on the scoreboard first in the 12th minute, taking advantage of a line-break by captain Michael Little. The Reds answered less than 10 minutes later, crossing the line with a powerful driving maul that the Sunwolves defense was unable to stop.

But tries from Rahboni Warren Vosayaco and Dan Pryor and two more conversions from Hayden Parker made it 21-5 at halftime.

The Reds, who came into Saturday's match having lost all three of their previous matches of the season, were playing without two of their Wallabies in prop Taniela Tupou and lock Izack Rodda.

But the Reds started the second stanza better, constantly putting the Sunwolves on the back foot and ensuring most of the action took place in the Sunwolves' half.

Three tries in a seven-minute stretch saw the visitors take the lead with replacement hooker Brandon Paenga-Amosa, who has four caps for the Wallabies, bagging a brace and replacement prop Harry Hoopert, playing in his second Super Rugby season, also scoring to make it 26-21 with less than 15 minutes remaining in the game.

The Sunwolves, however, fought back and a try by Keisuke Uchida converted by Parker, who then added a penalty saw them retake the lead.

But the visitors tied things up when Tate McDermott ran onto a charged-down kick and although Stewart missed the conversion he made amends a few minutes later with his killer-blow penalty.

"Overall, the second half was disappointing after we had put ourselves in a good position," said Sunwolves interim head coach Scott Hansen. "Their momentum led to us slowing off tackles and allowed the Reds back. And in the end, they were deserved winners."

Reds head coach Brad Thorn was naturally delighted with his team's comeback.

"I was proud of the whole team today," Thorn said. "We regrouped at halftime. The guys didn't stop believing and showed what we can handle."