Age has been proving no barrier for three of football's modern greats this week. On Tuesday, 34-year-old Lionel Messi opened his account for Paris Saint-Germain in spectacular fashion in their <a href="https://www.thenationalnews.com/sport/football/2021/09/29/psg-v-manchester-city-champions-league-ratings-messi-8-mbappe-9-grealish-5/" target="_blank">2-0 win against Manchester City</a> in the Champions League. The Argentine picked up the ball near the halfway line before playing a one-two with Kylian Mbappe and firing an unstoppable finish past City goalkeeper Ederson. City manager Pep Guardiola - Messi's old coach at Barcelona - <a href="https://www.thenationalnews.com/sport/2021/09/29/pep-guardiola-praises-unstoppable-messi-after-champions-league-defeat/" target="_blank">described his old player as "unstoppable"</a>. Fast forward 24 hours and it was Messi's old rival Cristiano Ronaldo's turn to step up to the plate. The 36-year-old scored an injury-time winner as <a href="https://www.thenationalnews.com/sport/football/2021/09/30/manchester-united-v-villarreal-ratings-de-gea-9-ronaldo-7-rulli-5-capoue-6/" target="_blank">Manchester United came from behind to beat Villarreal</a> in the Champions League. It was Ronaldo's 135th strike on his 178th appearance in the competition, leaving the Portuguese 15 goals clear of second-placed Messi at the top of the all-time Champions League scoring chart. Then, on Saturday night, Luis Suarez was making his mark once again in La Liga. The 34-year-old Uruguayan scored for <a href="https://www.thenationalnews.com/sport/football/2021/10/03/atletico-madrid-v-barcelona-ratings-lemar-9-suarez-8-araujo-3-depay-6/" target="_blank">Atletico Madrid in their 2-0 win over Suarez's old club Barcelona</a>, a result that piled more pressure on the Catalan club's manager Ronald Koeman. In the gallery above, we have picked out 25 of the most memorable images from a busy week of football action - and the rest of the sporting world.