Al-Tikriti, a Sunni, served with the counter-terrorism forces of the Iraqi army's Golden Division, which was tasked with protecting the refinery.
Soldiers from the counter-terrorism forces reported that ISIL fighters had been taunting the refinery protection force, saying "Come to face us, you rafidis" (rejecters, a derogatory term for Shia).
In return, al-Tikriti came out shouting, "I am Iraqi; I am Sunni and will not let you enter the refinery, even if this is over my dead body. I am for Iraq and for my 'rafidi' brothers", his colleagues reported him as saying.
Al-Tikriti's brother Maytham Mohammed described how his brother died.
"On that day the terrorist killers launched their fiercest attack on the refinery," he told Mawtani. "Fighters, along with my brother Wissam, defended the location with honour and the attacking terrorists were killed and their vehicles were burnt," he said.
"Wissam began firing at them while moving towards them," Mohammed said. "He aimed a number of rockets at them from his shoulder launcher and moved close to them after passing the concrete blocks."
"In the course of fighting, my brother went on top of a tank advancing towards him which had been rigged with explosives. As soon as he started to shoot those inside it, it exploded and he died as a result," he said.
"My martyred brother recorded the highest meanings of heroism, courage, protection of honour and the nation, protecting its people from the evils of terrorists until he became a martyr, raised the heads of his family members and became a medal on our chests," Mohammed said.
'A REAL HERO'
Al-Tikriti was born in Tikrit in Salaheddine province. He was known for his courage and selflessness, according to Hassan Faleh, a close friend who served with him in the counter-terrorism regiment.
"Wissam was a real hero who did not fear death, had great morals and everyone loved him for his dedication to duty and his sense of national responsibility," Faleh said.
Courage in battle was one of Wissam's attributes, Faleh said, adding that his friend had been "a source of pride" to others in the regiment.
"He once grew a beard, disguised himself in a uniform like the one worn by ISIL elements and attacked Abu al-Jawary area in al-Dhuluiya region with a number of other soldiers, killing about 10 ISIL terrorists and returning with his colleagues, unharmed," he said.
"Wissam also helped stop many attempts by ISIL elements to capture Baiji refinery and inflicted heavy losses in lives and equipment on the ranks of the enemy every time," he added.
In addition to his distinguished service, Mohammed said his brother excelled at the military academy where he graduated among the top students of his class.
"Wissam is an example of the heroic Iraqi fighter who does not hesitate to confront the enemy and sacrifice himself in defence of the homeland and the people of his country," counter-terrorism unit spokesman Sabah al-Numan told Mawtani.
"The martyr fought a lot of battles against the criminal gangs of ISIL in Salaheddine province, and managed with his brothers in the protection force to repel all terrorist attacks on the Baiji refinery with a strong spirit and high combat morals that always halted the enemy and led to its defeat," he said.
A SOURCE OF PRIDE
Local residents told Mawtani of their admiration for al-Tikriti, while others posted his photograph on their social media accounts with comments that reflect their pride in him.
"The martyrdom of 1st Lt. Wissam is an indicator of unity and national cohesion among all Iraqi people who are today facing an enemy […] that targets all Iraqis" regardless of sect or ethnicity, said Saad Majid, 37.
"The martyr Wissam has become an immortal national symbol in our memories and a role model for young Iraqis who refuse sectarianism and consider the love of country superior to all other considerations," 25-year-old student Huda Ali told Mawtani.
"I loved his dedication and courage on the battlefield, and shared his photos and heroic acts with my friends on Facebook," Ali said.
"We are very proud of the sacrifice of the martyr Wisam," said Tariq Mahdi, 41. "This young hero deserves a memorial to commemorate his role and sacrifice that has become today a clear indication of the brotherly links among all Iraqis."