Lionel Messi scored twice on his return from a hamstring injury as Barcelona beat Getafe 4-0 in Wednesday's Copa del Rey action.
Messi - who had not played for Barca since limping off in the first half of a 4-1 La Liga win against Real Betis on November 10 - was introduced in the 64th minute for Andres Iniesta in the round of 16 clash.
And he marked his comeback with two goals, making him likely to start for the Catalan giants in their La Liga blockbuster at Atletico Madrid on Saturday.
Fabregas nodded Barcelona into the lead in the ninth minute at Camp Nou, thanks to an excellent cross from Pedro.
His ball in from the left was met powerfully by the former Arsenal captain, who headed back across goal and left Getafe goalkeeper Jordi Codina with no chance.
Fabregas then sealed the victory in the 63rd minute, scoring from the penalty spot on this occasion.
Again the in-form Pedro was involved, with the 26-year-old hauled down in the area, and Fabregas powered his spot-kick into the top left corner.
Diego Castro went close for Getafe in the final 15 minutes, but saw his curling effort go just wide.
And despite the absence of forward Neymar, who was sidelined with gastroenteritis, Messi bagged two late goals - first converting from close range before a long run was followed with a typically composed left-foot finish.
The second leg between the two sides will be played on January 16.
Other scores in the first leg of the round-of-16 matches on Wednesday saw La Liga strugglers Real Betis defeat Athletic Bilbao 1-0.
Ruben Castro scored the game's only goal with a firm header, as the bottom-placed Betis won for the first time since December 6.
Second-tier Alcorcon beat Espanyol 1-0 thanks to Dani Pacheco's late goal and Racing Santander and Almeria played out a 1-1 draw.
|Coach: G. Martino|
for Iniesta 64'
for A. Sánchez 75'
for Fàbregas 81'
|Berardi will get Italy call when system changes - Ventura|
|Lucas Vazquez delighted by ´dream´ Madrid deal|
|Scottish FA chief backs cross-border competition|
|Dortmund need Reus - Aubameyang|
|Lamela eyeing new Spurs deal|
|Tighter Watford matches are a coincidence, says Mazzarri|
|Karanka: We saved Boro from League One|
|Police investigate homophobic leaflet at West Ham|
|Spain could recall Villa, reveals Lopetegui|
|Hughes backs Bony to break Stoke duck|
|Sarri will greet Higuain ´like a son who made him angry´|
|Robben receives Netherlands recall|
|Dyche considering Gray recall for Burnley|
|Zidane was behind one of my best seasons, says Ronaldo|
|Schweinsteiger absent from United squad photo|
|Emery emphasises Thiago Silva´s importance amid Juve links|
|Ferguson: Leicester will make deep Champions League run|
|Ranieri hails ´special´ Ballon d´Or nominations for Vardy and Mahrez|
|Emery: PSG cannot rely solely on Cavani goals|
|Mourinho can match Guardiola, insists Ferguson|
|Ferguson hails Klopp: Liverpool are strong title contenders now|
|Bayern optimistic over Lewandowski renewal|
|Zubizarreta appointment confirmed by Marseille|
|Clichy: Things will click into place for Manchester City|
|Chiellini: Juventus wanted to send a message|
|Gabigol´s time will come - De Boer|
|Ronaldo: Messi and I are not friends - but we respect each other|
|Earthquake halts play in Serie A game between Pescara and Atalanta|
|Mourinho charged over Taylor comments|
|Ronaldo: I need my haters|
|Badstuber hopeful injury woes behind him|
|Kroos did not want to be rested, insists Zidane|
|Rojo was phenomenal - Mourinho|
|Seven arrests made after West Ham - Chelsea fan clashes|
|Florenzi injury blow for Roma|
|MLS Review: Galaxy, Toronto into semis|
|Beister: Victory move surprised people|
|Bilic: Cup run will help in Premier League|
|Pjaca out for up to three weeks|
|Trophies still the focus for Guardiola|
|Mignolet wants ´fair´ Karius battle|
|Ancelotti impressed by motivated Bayern|
|West Ham ´unreservedly condemn´ crowd trouble|
|Allegri praises strike duo after win over Sampdoria|
|De Boer praises two-goal Icardi after vital win|
|Chelsea were ´unlucky´ with missed chances, insists Conte|
|Mourinho: I´ve never had fans like these|
|Nacho´s goal better than my Champions League final volley - Zidane|
|Borussia Dortmund 1 Union Berlin 1 (aet, 3-0 pens): Weidenfeller shootout heroics seal progress|
|Bilic: Crowd trouble distracts from great West Ham win|
|Kompany told me he couldn´t play anymore - Guardiola|
|Liverpool and Manchester United handed home quarter-finals|
|Inter 2 Torino 1: Icardi double alleviates pressure on De Boer|
|Manchester United 1 Manchester City 0: Mata extends Guardiola´s winless run|
|West Ham 2 Chelsea 1: Crowd trouble tarnishes Hammers´ route to quarter-finals|
|Cultural Leonesa 1 Real Madrid 7: Morata and Asensio star in BBC´s absence|
|Bayern Munich 3 Augsburg 1: Green´s first goal sends holders through|
|Juventus 4 Sampdoria 1: Rapid start sets champions on their way|
|Crafty Suarez is world´s best striker - Godin|
|Mancini: Balotelli has wasted years but can bounce back|
|Rami rejected ´risky´ PSG move|
|Neymar would have cost PSG €430m, claims father|
|Sacchi warns Bayern players over Ancelotti temper|
|Valencia ´pleased´ with RFEF bottle ruling|
|Mourinho apologises to Utd fans for Chelsea thrashing|
|Barcelona lash out at ´totally reprehensible´ RFEF comments|
|Jacob leaves Marseille amid rumours of Zubizarreta appointment|
|Lavezzi added to Argentina squad as Dybala drops out|
|Del Bosque: Mourinho had a point on Conte|
|N´Zonzi in talks over Sevilla extension|
|Allardyce successor ´will not be a mercenary´ - Glenn|
|Aubameyang like a rocket, Lewandowski perfect - Riedle|
|RFEF fines Valencia, warns Barca over bottle incident|
|Wenger tells Iwobi to improve his finishing|
|Barcelona without Mathieu for three weeks|
|Kimmich draws inspiration from Xavi|
|Vazquez signs new Madrid deal|
|Higuain the best striker in the world - Nedved|
|Wolfsburg regret De Bruyne, Perisic sales|
|Parejo slams Neymar for ´inciting´ Valencia fans|
|Gundogan predicts ´very lively´ Manchester derby|
|Luis Enrique satisfied with Supercopa workout|
|Messi could join Newell´s after World Cup - Maxi Rodriguez|
|Ibrahimovic wants United to be the boss of City|
|Schmidt on the bus as Lotte book ticket for next round|
|Pogba still adapting to Premier League, says Mourinho|
|Southgate hails influence of demoted Rooney|
|Lille ready to heap more pressure on PSG as Corchia dreams big|
|I´m among top 20 LaLiga coaches, jokes Luis Enrique|
|Brattan earns Socceroos call-up|
|Pochettino pleased with Janssen|
|Klopp never questioned Sturridge quality|
|Barcelona downed by Espanyol in Supercopa|
|Heavy Milan defeat ´just a bump in the road´ - Montella|
|Pochettino wanted Liverpool debutant sent off|
|Klopp happy to entertain as Liverpool youngsters earn their spurs|
|Leverkusen dumped out by 10-man minnows|