Bremen needed 30 minutes to gain a foothold into the game as Joshua Sargent tested Alexander Scholow with a long-range effort.
The second half saw Sharjah take the first lead after Moroccan defender Medhi Benatia received a red card for an elbow on Sharjah playmaker Igor Coronado, who beat the goalkeeper with a curled effort, but the ball bounced off the upright and fell to midfielder Majed Surour whose diving header help Sharjah establish the lead for the first time in the tie.
To keep fit, the club is holding separate training sessions of not more than five players each at different locations while beefing up its squad in readiness for continental football and defending their crown.
However, under the eccentric tutelage of coach Marcelo Bielsa, Leeds refused to lie down, and equalized in the 12th minute through Jack Harrison after a fine counter-attack.
In the 28th minute, thanks to a short cross from Cedric Bakambu on the midfield, Renato Augusto dribbled through defender Ding Haifeng and contributed a calm tap-in to pull one back.
Bale returns to the club he left to join Madrid in 2013 for a then-world record transfer fee of over 110 million U.S. dollars.
The Spain international's deal should also be confirmed on Friday, although he won't take part in Sunday's important league fixture which sees Liverpool travel to face big-spending Chelsea. Enditem
Villarreal coach Unai Emery will be looking for more cohesion in attack and his side will be favorites against Eibar, whose first game of the season was a dull 0-0 draw with Celta Vigo.
"I believe in Arsenal. We can achieve big things together. We have something exciting here and I believe the best is yet to come," he added.
"I'm really happy that it finally worked out," said Liverpool manager Jurgen Klopp. "I'm really happy to bring this wonderful person in as an add-on to the squad." Enditem
Granada dedicated the rest of the game to conserving energy ahead of their weekend La Liga game at home to Alaves, while the home side were reduced to 10 men in the 80th minute after Fabjan Beqja was sent off for two yellow cards.