Bohemians trialist Eric Molloy struck a last-gasp equaliser to ensure Frank Lampard's first game in charge of Chelsea ended in a 1-1 draw.
Michy Batshuayi scored the first goal of Lampard's reign in the first half as the Blues looked to get off to a winning start under the former Chelsea midfielder.
But Molloy produced an excellent finish in the 89th minute to leave Lampard waiting for his first win since being appointed head coach at Stamford Bridge.
How Lampard's Chelsea fared
Before kick-off all eyes were on Lampard's first team sheet and the new Blues head coach opted for a 4-2-3-1 formation.
Chelsea's first-half team
Caballero, Sterling, Azpilicueta, Guehi, Kenedy, Drinkwater, Ampadu, Pedro, Gallagher, Palmer, Batshuayi.
His first starting line-up included Cesar Azpilicueta at centre-back, while Danny Drinkwater partnered Ethan Ampadu and Kasey Palmer in midfield as Lampard opted for a blend of youth and experience.
It was Batshuayi, included as a lone striker, who impressed during the opening 45 minutes.
The Belgium international looked extremely sharp and he was rewarded with the first goal of the Lampard era, firing home from close range in the eighth minute after Kenedy's shot was deflected into his path.
Lampard rung the changes at the break, swapping out all 11 players to give his whole squad a run out at Dalymount Park.
Chelsea's second-half team
Cumming, Zappacosta, Chalobah, Zouma, Maatsen, Baker, Bakayoko, Brown, Gilmour, Piazon, Ugbo.
Tiemoue Bakayoko and Kurt Zouma, who both spent last season away from Stamford Bridge, were given a run out alongside youngsters Lewis Baker, Izzy Brown and Billy Gilmour.
Bakayoko and Gilmour went close to doubling Chelsea's advantage, but goalkeeper James Talbot produced two excellent saves before the hosts grabbed a dramatic 89th-minute equaliser.
Chelsea gifted possession to Keith Ward, who slid the ball through for Molloy and he took full advantage to level the scores.
The visitors had one final chance to secure victory but Ike Ugbo failed to turn home Brown's cross from close range as Bohemians held on for a draw.
Chelsea's remaining pre-season fixtures...
- July 13: St Patrick's Athletic - Richmond Park, Ireland
- July 19: Kawasaki Frontale - International Stadium, Japan
- July 23: Barcelona - Saitama Stadium, Japan
- July 28: Reading - Madejski Stadium
- July 31: RB Salzburg - Red Bull Arena, Salzburg
- August 3: Borussia Monchengladbach - Borussia Park, Germany