Cristiano Ronaldo made an immediate impact on his return from a COVID-19 infection on Sunday, scoring three minutes after coming on as a substitute before converting a penalty to lead Juventus to a 4-1 Serie A win at Spezia.
Spain and Portugal played out an entertaining 0-0 draw on Friday as both sides prepared for this month's European Championship.
The win put United back in second place in the Premier League, still 13 points behind neighbours Manchester City, while Chelsea drop below Tottenham into fifth place.
Arsenal enjoyed a 3-0 win in Azerbaijan against Qarabag in the Europa League on Thursday and AC Milan beat Greece's Olympiakos Piraeus 3-1 but Sevilla suffered a shock defeat by Russians Krasnodar.
Ibrahimovic has not played since suffering a career-threatening knee ligament injury in United's Europa League quarter-final second leg match against Anderlecht at Old Trafford in April.
A summary of the opening day's action in the UEFA Champions league on Tuesday.
Ibrahimovic and Lukaku, who played together at Manchester United, exchanged words at the end of the first half before the pair had to be restrained as the players left the pitch for the interval.
Juventus shattered Real Madrid's dream of a record-extending 11th European crown when Alvaro Morata scored against his former club to secure a 1-1 Champions League draw with the holders on Wednesday and send Juve into the final 3-2 on aggregate.
Barcelona captain Lionel Messi scored two goals and set up two more as the Catalans thrashed Real Valladolid 5-1 to move top of La Liga on Tuesday.
A round-up of Saturday's action in LaLiga, Ligue 1 and Serie A.
Morata became the first ever Spanish player to score for club and country at Wembley Stadium.
A summary of Thursday's matches in the English Premier League.
Images from the international friendly and Euro qualifying football matches played on Tuesday.
An early goal from Pablo Sarabia earned Spain a 1-0 win in Switzerland on Thursday, their first victory of this year's UEFA Nations League.
The 24-year-old has scored three league goals already and Shevchenko, who never replicated his superb goalscoring record for AC Milan in three subsequent years at Chelsea, believes there is much more to come from the Spaniard.
Each Round of 16 game was entertaining. Laxmi Negi/Rediff.com picks the games to remember.
Inter Milan got a crucial 1-0 win at Juventus on Sunday
Real Madrid thrashed Deportivo La Coruna 6-2 to stay level with Barcelona at the top of La Liga on Wednesday after the Catalans crushed Osasuna 7-1, condemning the minnows to relegation.
Chelsea a 1-0 win over Manchester United in a compelling Premier League clash on Sunday
Juventus need to beat Manchester City to reach the Champions League knockout stages on Wednesday and many fans still believe the best way to achieve this is by fielding Alvaro Morata and Paulo Dybala together in attack.
Atletico midfielder Saul Niguez, however, criticised his side for not showing enough ambition early in the game.
Real Madrid captain Sergio Ramos performed another rescue act to wreck Napoli's brave comeback attempt and take the Champions League title-holders into the quarter-finals.
Friday's win should add weight to the predictions of many that Spain are favourites to capture a third straight European title.
'It wasn't easy, but I called him last night (Sunday) and we had a difficult and tough conversation. I feel bad as he's a player who has always been at the top level and has a future with the national team.'
Diego Costa scored four goals as Real Madrid were embarrassed 7-3 by rivals Atletico Madrid in the final match of their United States tour, in New Jersey, on Friday
Italy are one win away from being crowned champions of Europe
Morata to stay on loan at Juventus for another season
It has been a long time coming but Spain look as if they may finally have solved their number nine problems following Alvaro Morata's two goals in the 3-0 win over Turkey.
Chelsea manager Antonio Conte was fuming at the final whistle after Pedro and Alvaro Morata were dismissed in extra time and two penalty appeals had been waved away, but the Premier League champions regained their composure to win the shootout 5-3.
Juventus may have become the only club to lose six European Cup finals but they took heart from pushing Barcelona to the limit in Saturday's riveting final and restoring the honour of Italian football, coach Massimiliano Allegri said.
Defender Miguel Britos was sent off for head-butting an opponent as Napoli lost 3-1 at champions Juventus on Saturday, all but ending their hopes of Champions League football next season.
Alvaro Morata again proved decisive from the bench by striking a late winner against Athletic Bilbao and firing a lacklustre Real Madrid to the top of La Liga on Sunday. The Spain international has been afforded limited opportunities in his first season back at Real following two years with Juventus, struggling to usurp first choice forwards Gareth Bale, Cristiano Ronaldo and Karim Benzema. Morata has made just four league starts, but has scored four times in all competitions.
Premier League champions Chelsea eased past a disappointing Everton with goals from Spaniards Cesc Fabregas and Alvaro Morata sealing a 2-0 victory on Sunday.
Italy's ability to get over the line in by far their biggest challenge of the Euros so far has made many people on the peninsula more convinced than ever of their ability to go on and win it on Sunday.
Goals in each half from Kai Havertz and Christian Pulisic earned defending champions Chelsea a solid 2-0 first-leg victory over Lille in the Champions League last 16 on Tuesday.
Juventus striker Carlos Tevez scored a second-half penalty as the hosts beat holders Real Madrid 2-1 in the Champions League semi-final, first leg, on Tuesday.
Tottenham Hotspur claimed a first victory at Chelsea for 28 years with Dele Alli scoring twice in the second half as they came back to win 3-1 and cement fourth place in the Premier League on Sunday.
Real Madrid paid more than 200 million euros ($227.76 million) to assemble their forward line of Cristiano Ronaldo, Gareth Bale and Karim Benzema, but the attacking trio failed them again in Wednesday's Champions League exit to Juventus.
Images from the EPL matches played on Sunday
Cristiano Ronaldo and Gareth Bale both scored as Real Madrid staged a remarkable late comeback from two goals down to win 3-2 at Villarreal and stay top of La Liga.