Urawa Reds as good as wrapped up the J. League first-stage title but were forced to leave the champagne on ice after beating Shimizu S-Pulse 1-0 on Sunday.

Reds went into the game knowing that a win over lowly S-Pulse coupled with a defeat for second-place Gamba Osaka would see them clinch their first piece of silverware since winning the Asian Champions League title in 2007.

A 52nd-minute goal from Shinzo Koroki kept up Urawa’s side of the bargain, but a 0-0 draw between Gamba and Vissel Kobe forced the 44,424 crowd at Saitama Stadium to postpone their celebrations for another day.

Urawa’s first-stage victory now looks simply a formality, however, as a nine-point gap separates the leaders from Gamba. Defending champions Gamba are the only other team mathematically still in contention, but must win their remaining three games and hope that Reds lose their remaining two.

Urawa’s penchant for self-destruction — blowing a five-point lead with three games to play last season to hand the title to Gamba — means manager Mihailo Petrovic is taking nothing for granted. But the Serbian insists his team has learned from its mistakes.

“Today’s result was one born from experience. Last year we had a chance to clinch the title here against Gamba, and although we were the better team in that game, we lost,” Petrovic said of the 2-0 defeat that began Urawa’s downfall last season.

“Today we didn’t play so well, but the players knew that the most important thing was to win no matter what.”

The J. League has this season reverted to the two-stage system it last used in 2004, but with format tweaks that place more importance on overall points than winning the first or second stage.

Reds have now set an all-time J. League record in starting this season unbeaten over 15 games, and Koroki is keen to maintain the spirit that has seen his side collect 37 points from a possible 45.

“We aren’t always playing well, but the results are the most important thing,” said Koroki, who won three league titles with Kashima Antlers from 2007-09.

“In the past, if we had played badly we would have lost. The fact that we didn’t today proves our strength. I’ve won league titles before, and there are times over the season where you are in good and bad form. If you can pick up points when you’re playing badly, it’s very important.”

Urawa dominated the early stages but both sides created chances, with Tadanari Lee blasting a Yuki Muto cross over the S-Pulse bar before Reds goalkeeper Shusaku Nishikawa denied Mitchell Duke with a sharp save at the other end.

Lee narrowly failed to redirect a Muto shot into the net with halftime approaching, before Tomoaki Makino almost got the second period off with a bang when he ghosted in at the far post five minutes after the restart.

But minutes later, Koroki gave Urawa the lead. The striker dummied a defender to make space for himself after receiving the ball in the box, then lashed home a left-foot shot that slid beyond the reach of goalkeeper Masatoshi Kushibiki.

Koroki almost added another with a close-range snap shot in the 65th minute, but in the end one goal was enough as Urawa hung on despite late chances for the visitors.

“Our theme for this year is patience,” said Urawa midfielder Yosuke Kashiwagi. “You could see that from our performance in the second half.”

Elsewhere in the J. League, Sanfrecce Hiroshima jumped into second place but were eliminated from first-stage title contention despite a 3-2 win over Kashiwa Reysol.

FC Tokyo also leapfrogged Gamba into third after a 2-1 win over Matsumoto Yamaga, while Yokohama F. Marinos stayed fifth after a 1-1 draw with Ventforet Kofu.

Vegalta Sendai turned on the style to thrash Sagan Tosu 5-0, Elsinho hit a 94th-minute winner as Kawasaki Frontale beat Shonan Bellmare 2-1, and Montedio Yamagata and Kashima Antlers drew 2-2.

In the day’s other game, Albirex Niigata and Nagoya Grampus drew 1-1.