There was just a hint of a smile playing around the corners of Mircea Lucescu's mouth when the final whistle blew last Saturday, signalling a victory for his current team Dynamo Kiev over their great rivals Shakhtar Donetsk, the side he ruled for over a decade.

The 75-year-old is in his first season as head coach at Dynamo but that 1-0 win over his old team at the Olympiysky stadium in Kiev means he is just one win away from delivering the club's first league title in five years.

With a 10-point lead over their rivals and just four games to go, it should be the sweetest moment for Lucescu.

But having spent 12 years in the Shakhtar hotseat, the Romanian's reticence in celebrating, is easy to understand.

"It's not easy for me," said Lucescu whose 40-year career includes stints in charge of the Romanian and Turkish national teams.

"It was difficult for me to organise the Dynamo play in such a short period of time and achieve the result. But we did it."

Dynamo can wrap up the title on Sunday if they beat Ingulets Petrove but whether that will convince the fans that Lucescu is the right coach for the club is another matter.

Lucescu's football history is only a part of the problem, albeit a big part.

His record with Shakhtar is extraordinary: between 2004 and 2016, he steered the club to an incredible 22 trophies, including the 2009 UEFA Cup. He was, and some might argue still is, 'Mr Shakhtar'.

Dynamo's decision last summer to bring him on board sparked an uproar from fans.

The ultras were, unsurprisingly, the most vocal, accusing Lucescu of having repeatedly spoken inappropriately about Dynamo and calling his appointment "a spit in the face of all Dynamo fans".

Lucescu was undoubtedly unsettled by the reaction and, just two days after signing a two-year contract in July, announced his intention to quit.

That he subsequently reversed his decision was down to the support of the Dynamo president, Igor Surkis.

Beyond football, however, lies the geopolitics of a region that has effectively been on a war footing since Russia annexed the previously Ukrainian-controlled Crimean peninsula in 2014.

Many Dynamo fans have still not forgiven Lucescu for comments he made back in 2016.

"Russia and Ukraine are one and the same country for me," he said.

"They (the countries) were separated by chance. But for my peers, this is all the former Soviet Union."

Dynamo's most radical fans are not shy about displaying their nationalism.

Some joined government forces in a war with Russian-backed separatists in the east of the country which prompted Shakhtar to abandon their home city of Donetsk which was seized by the rebels in 2014.

Since Lucescu's first days in Kiev, dozens of fans used every opportunity to protest, lighting flares and chanting "Lucescu, go away!"

The fans' attitude has not budged, even when Dynamo, in Lucescu's first match against Shakhtar, beat his old club 3-1 to win the Ukrainian Super Cup in August.

After his initial reservations about the fans' reaction, Lucescu has grown a thicker skin.

"I don't consider them fans," he said this week. "I am interested in the play, the result, in making Dynamo better."

An excellent tactician with vast experience, Lucescu, has transformed Dynamo over the last nine months, without adding any high-priced recruits.

Dynamo could not cope with Barcelona and Juventus in their Champions League group but progressed to the last 16 stage of the Europa League, where they lost to Spanish side Villarreal.

This season's domestic performance is in stark contrast to last year's failure under Lucescu's predecessor Oleksiy Mykhailychenko when Dynamo finished second in the title race, a record 23 points behind Shakhtar.

"Lucescu, without changing the squad, is unexpectedly changing the result," Artem Frankov, the editor-in-chief of 'Football' magazine, told AFP.

"The available players have stepped up to the next level.

"He finds an individual approach to everyone. Lucescu's authority is unshakable and the players trust him."

This week the ultras said they would not trust Lucescu even if he delivered the Champions League but perhaps, after Sunday, even they might begin to change their tune.