Gamba now have 26 points but are still some distance behind leaders Kashima Antlers, who have 43 points.

Gamba were without suspended Japan midfielder Yasuhito Endo and struggled to find their pace throughout much of the match.

The north Osaka team were given an early scare when Reysol forward Hideaki Kitajima hit the bar in the 22nd minute.

Kitajima came close again shortly after the break when he connected with a crisp cross from Yusuke Murakami but his header flew over the bar.

But Gamba took the lead in the 52nd minute when Leandro was brought down by Reysol goalkeeper Takanori Sugeno in the box and the Brazilian forward stepped up to score from the penalty spot.

Reysol soon brought on two attacking players from the bench in a bid to get back into the game but instead Gamba went further ahead in the 68th minute when Leandro headed home Michirhiro Yasuda's cross.

A miserable day for the hosts was complete when defender Yuzo Kobayashi was shown his second yellow card for dissent in the 90th minute.

"It was far from our usual style but our players' hard work paid off, which was good," said Gamba coach Akira Nishino.

"This result can give our team much confidence."

In Hiroshima, Sanfrecce Hiroshima romped to a 4-1 win over lowly JEF United Chiba and moved up to sixth place from ninth.

Japan international Hisato Sato opened the scoring soon after the break and Ilian Stojanov added a second when he curled home a free-kick.

North Korea midfielder Ri Han-jae made it 3-0 with a strike in the final minute.

Chiba grabbed a consolation in stoppage time through Kohei Kudo but Toshihiro Aoyama then restored his side's three-goal advantage soon after.

Finally, Montedio Yamagata beat Jubilo Iwata 3-1 to move up to 11th with their second straight win.