A late Rotherham United winner failed to spoil a special occasion for Grimsby Town as more than 3,000 fans returned to Blundell Park for James McKeown's testimonial match.
As well as celebrating 10 years of loyal service by the keeper, the game marked the Mariners' biggest test of pre-season so far as they took on the League One Millers in what was an entertaining and competitive encounter.
The visitors controlled posession for long periods of the first half but McKeown made some good saves to keep them out and at the other end, Town created a number of opportunities of their own but were denied on a number of occaasions by stopper Viktor Johansson.
Town had more chances to take the lead after the interval, with Erico Sousa among the new signings to impress on their home debuts and provide a glimpse of what the Mariners fans can expect when the National League season kicks off next month.
But when the deadlock was finally broken on 84 minutes, it was Rotherham who secured the win as Michael Ihiekwe scored from close range.
A strong Town line-up began the game as seven of the club's summer additions pulled on the black and white shirt at Blundell Park for the first time.
McKeown started in goal behind a defence of Michee Efete, David Longe-King, Luke Waterfall and Adam Crookes, while Harry Clifton, Giles Coke and Ben Fox made up a midfield trio as Sousa, John McAtee and Joel Grant formed the attack.
Rotherham also named a strong XI as they continued to build up to the start of their league campaign on August 7.
After a guard of honour was formed for McKeown, the game kicked off amid a noisy atmosphere as the 3,008 fans made the most of being back inside the stadium.
The first attack saw the ball fall for Sousa but he could not get it fully under control and visiting keeper Johansson came out to deal with the danger.
Rotherham won the first corner of the game on three minutes but caused no problems from it, then a second away corner was headed clear by Waterfall before McKeown was called into action for the first time to smartly keep out a header from Michael Smith.
A cross from Waterfall on the right landed on the roof of the net after the ball broke for the centre-back following a Town free kick near the halfway line, then a Rotherham corner from the left led to McKeown tipping the ball over the bar for another one. This time, it was headed wide for a goal kick.
Town's first big chance of the game came on 14 minutes when Sousa was sent clear through the middle but he could not make it count as he was denied by keeper Johansson, who blocked the low shot.
Clifton also saw a shot well-saved by the keeper after more good play by Sousa and when the ball came back to the midfielder, he could only head off-target.
McKeown got down to stop a shot by Mickel Miller as the visitors threatened again on 26 minutes and Town survived again just after the half-hour when the keeper saved from Freddie Ladapo and the rebound from Chiedozie Ogbene hit the top of the bar.
The Mariners won a corner soon afterwards but Grant's delivery from it was headed clear, before a penalty shout on 41 minutes was waved away after Efete went down under a challenge inside the box.
A cross from Fox was headed clear as Town looked for an opening goal before half-time and the hosts remained on the attack during the one additional minute but were unable to create any further chances as an entertaining half ended goalless.
Rotherham had controlled possession for the majority of the half and created more chances but Town had been equal to everything thrown at them by visitors from two divisions higher in the pyramid and had also shown plenty of encouraging signs of their own.
Max Wright replaced Grant for the hosts before the restart, with Kieran Sadlier coming on in place of Smith for Rotherham.
An early cross from Shane Ferguson on the away left landed on the roof of McKeown's net, with a ball into the box from Clifton at the other end headed away.
Town threatened again on 53 minutes when McAtee got down the right and sent a cross over for Sousa, who headed wide.
McAtee headed clear from a Rotherham corner two minutes later, before a great move from the Mariners led to a good chance after Sousa won the ball and found McAtee on the right. His low cross went into the path of Clifton but the midfielder could not take the opportunity as he sliced his shot away from danger.
Josh Kayode replaced Miller for the away side on the hour, before Luke Spokes came into the Town midfield in place of Coke.
McAtee went down with an injury and was replaced by Edwin Essel on 70 minutes, while Shaun Pearson and Ryan Sears were also sent on at the same time as Waterfall and Efete made way.
Sousa won a corner on 72 minutes but Sears was unable to turn the winger's driven delivery towards goal at the near post.
Aaron Braithwaite replaced Fox in the latest Town change on 77 minutes, with Evan Khouri, Jaz Goundry and Harry Milner following as they came on for Crookes, Longe-King and Sousa soon afterwards. Jamie Bramwell was also given some game time as he replaced Clifton.
With the clock ticking down, it looked like the game might finish goalless but Rotherham made a breakthrough six minutes from time as a free kick from the left was not dealt with and IHIEKWE sent the loose ball into the net from close range in front of the 461 travelling supporters from South Yorkshire.
McKeown came off he pitch to a deserved standing ovation as he was replaced by Ollie Battersby for the closing stages of the game as Rotherham saw out the remainder of the contest to secure a victory.
But despite the defeat, there were plenty of positives for the Mariners and lots to whet the appetite of fans for the season ahead.
Town's next game at Blundell Park will be their first home fixture of the National League season against Weymouth on August 28.
Before that, the pre-season campaign continues, with the Mariners next in action when they visit Hyde United on Friday.