On 11th. February 1921, a successful ambush had been carried out on the Mallow-Tralee train at Drishanebeg, within the Second Cork Brigade area. A party of British troops travelling on the train had been attacked and defeated, one soldier being killed and several wounded. The attacking party suffered no casualties and had succeeded in capturing fifteen rifles and several hundred rounds of ammunition. No civilian casualties had occurred.

Following this, intelligence officer Florence O'Donoghue informed the headquarters of the Third (West Cork) Brigade that a party of British troops, probably twelve to fifteen in number, would leave Cork for Bantry on the 9.30 a.m. train on the 15th. February. Arrangements were made to send a coded message by telephone to Bandon on the morning of the 15th. to confirm the departure of the troops and giving details of their numbers and their location on the train.

Brigade Commander Charlie Hurley considered that the risk to civilians on the train would not be excessive so the ambush was decided upon. The location chosen was Upton station, four miles east of Bandon. As there was no time available in which to mobilise a battalion column for the operation, Hurley quickly got together a party of local volunteers along with acting Brigade Adjutant, Flor Begley and General Staff Officer, Sean Phelan.

The passenger platform of Upton station was on the north side of the rail line. On it were the station-master's house, ticket-booking office, waiting-room etc. Extending west from the buildings right up to the signal cabin was a timber fence with a wicket-gate exit. On the opposite side of the railway a goods store occupied the eastern end of the station, bounded by a low wall to the south. At the southern extremity there was a two-story public house.

Arriving at the station only a few minutes before the train was due to arrive Charlie Hurley ordered the attacking party into position. Pat O'Sullivan and John Butler were stationed at the toilets next to the waiting room, O'Sullivan armed with two .45 revolvers and Butler with a rifle. Flor Begley and Sean Phelan, both with Colt automatics, were in the waiting-room. Paddy O'Leary was positioned at the wicket gate and Sean Hartnett at the gable-end of the signal cabin, both armed with rifles. Charlie himself took up a position on the footbridge that spanned the line at the western end of the platforms, and was armed with a Peter the Painter with stock.

On the opposite side of the station Batt Falvey and Neilus Begley were posted at the goods store; Denis Desmond and Dan O'Mahony behind the low wall, and Paddy Coakley at a window upstairs in the public house. Finally, Tom Kelleher and Denis Doolan held positions behind a wall at the entrance to the goods yard. These seven men were armed with rifles. An attacking party of fourteen men in total were within the station and a number of local scouts were posted close by. Soon the noise of the approaching train could be heard. However, there had been an unforeseen development. A party of close on fifty soldiers from Kinsale Barracks had boarded the train at Kinsale junction (a station between Cork and Upton) and positioned themselves among the civilian passengers. A valiant effort was made to warn the ambush party by Bill Hartnett, a brother of Sean who was waiting to attack the train at Upton station who jumped on a bicycle and rode as fast as he could in the hope of reaching Upton before the train. He arrived only a couple of minutes too late.

As the train pulled into the station the attackers opened fire. This was immediately returned by the soldiers who poured out on to the platform. When Charlie Hurley saw that the enemy force now greatly outnumbered his own small group he gave the order for withdrawal, shouting to those on the south side to fall back towards the level crossing and gate house to the west of the station. His own gun jammed after the first shot, and as he jumped down from the bridge, he received a bullet wound in the face and also sprained his ankle.

Among the six on the north side casualties were heavy. Pat O'Sullivan was mortally wounded and Sean Phelan was shot down as he tried to escape through the waiting room window. Flor Begley, Paddy O'Leary, John Butler, and Sean Hartnett succeeded in getting clear although the latter was wounded. On the southern side Batt Falvey was shot through the head and died instantly. The others fell back to the level crossing, helped by the protecting fire of Tom Kelleher and Denis Doolan. When Doolan came upon the wounded Dan O'Mahony he carried him for over a mile to safety. Although O'Mahony recovered under treatment he died a few years later as a result of his wounds.

Tom Kelleher went to the assistance of Charlie Hurley who was seriously wounded and had no chance of escaping on his own. Kelleher practically carried him from the scene of the ambush, Hurley repeatedly begging his rescuer to leave him and make good his own escape. The courageous Kelleher insisted on bringing his wounded companion to safety and by late afternoon the pair reached the comparative security of Patsy Sheehan's house at Kilmore, where they rested for some time. They then moved on to Cloughduv where Hurley recuperated for some time. They eventually reached Brigade Headquarters at Denny Ford's of Ballymurphy.

Pat O'Sullivan, although seriously wounded, managed to escape from his position on the station platform and under the protection of a deep trench dragged himself out of the danger zone. On the following day Jack Kenefick of the First Cork Brigade conveyed O'Sullivan to the North Infirmary in Cork city but O'Sullivan died shortly after his arrival there.

The bodies of Sean Phelan, Batt Falvey and Pat O'Sullivan were laid to rest in the Republican plot at St Finbarr's cemetery in Cork.