Republic of Ireland's World Cup play-off tie with Denmark is finely poised after a 0-0 draw in the first leg in Copenhagen on Saturday.
The only clear chances of a tight encounter were in the first half as Darren Randolph made a sharp double save and Pione Sisto turned a rebound wide from a good position.
Ireland offered little in attack but almost hit on the break in the 44th minute as Cyrus Christie saw a shot saved by Kasper Schmeichel.
Randolph also tipped over a late header from substitute Yussuf Poulsen to ensure the tie is level ahead of the return leg at the Aviva Stadium on Tuesday, live on Sky Sports Football.
Player ratings
Denmark: Schmeichel (6), Ankersen (6), Kjaer (6), Bjelland (6), Larsen (6), Kvist (6), Delaney (6), Eriksen (5), Sisto (5), Cornelius (5), Jorgensen (5)
Subs: Poulsen (5), Bendtner (5)
Republic of Ireland: Randolph (8), Christie (7), Duffy (7), Clark (7), Ward (7), Hendrick (6), Arter (6), O'Dowda (6), Brady (5), McClean (5), Murphy (5)
Subs: Long (5), Whelan (5), Hourihane (5)
Man of the match: Darren Randolph
Ireland might well be the happier side after the first leg, having set up with a defensive gameplan in Copenhagen and allowed Denmark the majority of the possession.
The visitors did almost suffer an early setback as Randolph made a double save to deny Jens Stryger Larsen and then Andreas Cornelius.
Otherwise Ireland were relatively untroubled until the 33rd minute when Randolph could only palm out a shot from Christian Eriksen and Sisto failed to finish the rebound from close range.
Ireland's best moment of the first half came late on as Christie burst past Larsen down the right side and then saw his chipped shot saved by Schmeichel.
The visitors continued to hold their defensive shape after the break and neither side created any more clear chances until the final few minutes of the match.
Shane Duffy headed at Schmeichel from a free-kick before substitute Poulsen saw an effort tipped over by Randolph.
Team news
Republic of Ireland’s David Meyler missed out through suspension and was replaced by Callum O'Dowda of Bristol City. Andreas Cornelius, Andreas Bjelland, Peter Ankersen, Jens Larsen and Mathias Jorgensen started for Denmark as the hosts made five changes from their last match.
Opta stats
· Republic of Ireland are unbeaten in each of their last four play-off qualifiers away from home (W1 D3) and have avoided defeat in all of their fixtures on the road in this World Cup qualifying campaign (W3 D3).
· Indeed, Republic of Ireland have not lost any of their last five international meetings with Denmark (W2 D3), keeping clean sheets in each of the last three (W2 D1).
· The Boys in Green have kept three consecutive clean sheets for the first time since October 2015.
· However, this is the first time that Republic of Ireland have failed to score in an away international since November 2014; they had found the net in each of their last nine on the road prior to tonight.
Man of the match - Darren Randolph
Ireland set up to defend, and they restricted the hosts to few openings while keeping Eriksen, who had scored eight goals in qualifying, quiet throughout.
When Denmark did get through, they found Randolph in their way. The Middlesbrough goalkeeper made a double save early on and then kept out an effort from Eriksen before tipping over Poulsen's late header to ensure the game finished goalless.
The manager
Martin O'Neill: "I thought it was a tough evening for us and the players did splendidly. They put a lot of effort in and it's all to play for now.
"We have to win a game. And I think we have to score a couple of goals because Denmark are capable of scoring too."
What's next?
A World Cup spot is up for grabs when Republic of Ireland host Denmark in their second leg on Tuesday.